14Chapter33 Early Quantum theory and models of Atom
高等量子力学和量子力学的区别
高等量子力学和量子力学的区别英文回答：The difference between advanced quantum mechanics and quantum mechanics lies in the level of complexity and mathematical formalism used in each field. Quantum mechanics is the branch of physics that describes the behavior of particles at the atomic and subatomic level. It is based on a set of mathematical principles and equations, such as the Schrödinger equation, which can be used to calculate the probabilities of different outcomes in quantum systems.Advanced quantum mechanics, on the other hand, builds upon the foundation of quantum mechanics and delves deeper into more complex and abstract concepts. It involves the study of advanced mathematical techniques, such as group theory and operator theory, to describe and analyze quantum systems. Advanced quantum mechanics also explores topics like quantum field theory, quantum information theory, andquantum many-body systems.To illustrate the difference between the two, let's consider the concept of entanglement. In quantum mechanics, entanglement refers to the phenomenon where two or more particles become linked together in such a way that the state of one particle cannot be described independently of the state of the other particles. This is famously described as "spooky action at a distance" by Albert Einstein.In advanced quantum mechanics, the study of entanglement goes beyond just understanding its existence. Researchers in this field investigate how entanglement can be used for quantum teleportation, secure communication, and quantum computing. They develop more sophisticated mathematical tools to quantify and manipulate entanglement, such as entanglement entropy and entanglement swapping.In summary, while quantum mechanics provides the foundational principles and equations for understanding the behavior of particles at the quantum level, advancedquantum mechanics takes a more advanced and mathematical approach to explore complex phenomena and applications of quantum systems.中文回答：高等量子力学和量子力学的区别在于所涉及的复杂程度和数学形式主义的使用。
Quantum entanglement
Quantum entanglementMaciej LewensteinMaciej Lewenstein has obtained his degree in Physics from Warsaw University. From 1980 he worked at the Center for Theoretical Physics of the Polish Academy of Sciences. He received his doctoral degree in 1983 at the University of Essen and habilitation in 1986 in Warsaw. He became a full Professor in Poland in 1993. In 1995 he joined “Service de Photones, Atomes et Molecules” of CEA in Saclay. In 1998 he became a full professor and a head of the quantum optics theory group at the University of Hannover. In 2005 he started a new theory group at the “Insitut de Ciencias Fotoniques” in Barcelona. His research interests include: quantum optics, quantum information and statistical physics.Chiara MacchiavelloChiara Macchiavello finished her degree in Physics in 1991 and her PhD in 1995 at the University of Pavia. She held a post-doctoral for two years at the University of Oxford. Since 1998 she has been an Assistant Professor at the University of Pavia.Her research interests include quantum information processing and quantum optics.Dagmar BrussSince 2003 Dagmar Bruss is a professor at the Institute of Theoretical Physics at the University of Duesseldorf, Germany. Her research interests include the foundations of quantum information theory, classification of entanglement and quantum optical implementations of quantum computation.AbstractEntanglement is a fundamental resource in quantum information theory. It allows performing new kinds of communication, such as quantum teleportation and quantum dense coding. It is an essential ingredient in some quantum cryptographic protocols and in quantum algorithms. We give a brief overview of the concept of entanglement in quantum mechanics, and discuss the major results and open problems related to the recent scientific progress in this field.IntroductionEntanglement is a property of the states of quantum systems that are composed of many parties, nowadays frequently called Alice, Bob, Charles etc. Entanglement expresses particularly strong correlations between these parties, persistent even in the case of large separations among the parties, and going beyond simple intuition.Historically, the concept of entanglement goes back to the famous Einstein-Podolski-Rosen (EPR) “paradox”. Einstein, who discovered relativity theory and the modern meaning of causality, was never really happy with quantum mechanics. In his opinion every reasonable physical theory should exhibit a so called local realism.Suppose that we consider two particles, one of which is sent to Alice and one to Bob, and we perform independent local measurements of “reasonable” physical observables on these particles. Of course, the results might be correlated, because the particles come from the same source. But Einstein wanted really to restrict the correlations for “reasonable” physical observables to the ones that result from statistical distributions of some hidden (i.e. unknown to us and not controlled by us) variables that characterize the source of the particles. Since quantum mechanics did not seem to produce correlations consistent with a local hidden variable (LHV) model, Einstein concluded that quantum mechanics is not a complete theory. Erwin Schrödinger, in answer to Einstein’s doubts, introduced in 1935 the term “Verschränkung” (in English “entanglement”) in order to describe these particularly strong quantum mechanical correlations.Entanglement was since then a subject of intense discussions among experts in the foundations of quantum mechanics and philosophers of science (and not only science). It took, however, nearly 30 years until John Bell was able to set the framework for experimental investigations on the question of local realism. Bell formulated his famous inequalities, which have to be fulfilled in any multiparty system described by a LHV model. Alain Aspect and coworkers in Paris have demonstrated in their seminal experiment in 1981 that quantum mechanical states violate these inequalities. Recent very precise experiments of Anton Zeilinger’s group in Vienna confirmed fully Aspect’s demonstrations. All these experiments indicate the correctness of quantum mechanics, and despite various loopholes, they exclude the possibility of LHV models describing properly the physics of the considered systems.Entanglement has become again the subject of cover pages news in the 90’s, when quantum information was born. It was very quickly realized that entanglement is one of the most important resources for quantum information processing. Entanglement is a necessary ingredient for quantum cryptography, quantum teleportation, quantum densecoding, and if not necessary, then at least a much desired ingredient for quantum computing.At the same time the theory of entanglement is related to some of the open questions of mathematics, or more precisely linear algebra and functional analysis. A solution of the entanglement problem could help to characterize the so called positive linear maps, i.e. linear transformations of positive definite operators (or physically speaking quantum mechanical density matrices, see below) into positive definite operators.Entanglement of pure statesIn quantum mechanics (QM) a state of a quantum system corresponds to a vector |Psi> in some vector space, called Hilbert space. Such states are called pure states. One of the most important properties of QM is that linear superpositions of state-vectors are also legitimate state-vectors. This superposition principle lies at the heart of the matter-wave dualism and of quantum interference phenomena.Entanglement is also a result of superposition, but in the composite space of the involved parties. Let us for the moment focus on two parties, Alice and Bob. It is then easy to define states which are not entangled. Such states are product states of the form |Φ>= |a>|b>, i.e. Alice has at her disposal |a>, while Bob has |b>. Product states obviously carry no correlations between Alice and Bob. Entangled pure states may be now defined as those which are superpositions of at least two product states, such as|Φ> = α1|a1>|b1> + α2|a2>|b2> + etc.but cannot be written as a single product state in any other basis. All entangled pure states contain strong quantum mechanical correlations, and do not admit LHV models.Entanglement of mixed states and the separability problemVerify whether a given state-vector is a product state or not is a relatively easy task. In practice, however, we often either do not have full information about the system, or are not able to prepare a desired state perfectly. In effect in everyday situations we deal practically always with statistical mixtures of pure states. There exists a very convenient way to represent such mixtures as so called density operators, or matrices. A density matrix rho corresponding to a pure state-vector |Φ> is a projector onto this state. More general density matrices can be represented as sums of projectors onto pure state-vectors weighted by the corresponding probabilities.The definition of entangled mixed states for composite systems has been formulated by Reinhard Werner from Braunschweig in 1989. In fact, this definition determines which states are not entangled. Non-entangled states, called separable states, are mixtures of pure product states, i.e. convex sums of projectors onto product vectors:ρ = Σι pi|ai>|bi><ai|<bi|, (*)where 0 ≤ pi ≤ 1 are probabilities, i.e. Σιpi= 1. The physical interpretation of thisdefinition is simple: a separable state can be prepared by Alice and Bob by using local operations and classical communication. Checking whether a given state is separable or not is a notoriously difficult task, since one has to check whether the decomposition (*) exists or not. This difficult problem is known under the name of “separability or entanglement problem”, and has been a subject of intensive studies in the recent years.Simple entanglement criteriaThe difficulty of the separability problem comes from the fact that rho admits in general an infinite number of decompositions into a mixture of some states, and one has to check whether among them there exists at least one of the form (*). One of the most powerful necessary conditions for separability has been found by one of the fathers of quantum information, the late Asher Peres. Peres (Technion, Haifa) observed that since Alice and Bob may prepare separable states using local operations, Alice may safely reverse the time arrow in her system, which will change the state, but will not produce something unphysical. In general, such a partial time reversal is not a physical operation, and can transform a density operator (which is positive definite) into an operator that is no more positive definite. In fact this is what happens with all pure entangled states. Mathematically speaking partial time reversal corresponds to partial transposition of the density matrix (only on Alice's side). We arrive in this way at the Peres criterion: If a stateρis separable then its partial transposition has to be positive definite.This criterion is usually called positive partial transpose condition, or shortly PPT condition. Amazingly, the PPT condition is not only necessary for separability, but it is also a sufficient condition for low dimensional systems such as two qubits (dimension 2x2)and a system composed of one qubit and one qutrit (dimension 2x3). In higher dimensions, starting from 2x4 and 3x3, this is no longer true: there exist entangled states with positive partial transpose, which are called PPT entangled states.There exist several other necessary or sufficient separability criteria which have been established and frequently discussed in recent years. For example, states that are close to the completely chaotic state (whose density operator is equal to the normalized identity) are necessarily separable. There exist also other criteria that employ entropic inequalities, uncertainty relations, or an appropriate reordering of the density matrix (so called realignment criterion) etc. There exists, however, no general simple operational criterion of separability that would work in systems of arbitrary dimension.Entanglement witnessesThe set of all states P is obviously compact and convex. If ρ1 and ρ2are legitimate states,so is their convex mixture. The set of separable states S is also compact and convex (seeFigure 1). From the theory of convex sets and Hahn-Banach theorem we conclude that for any entangled state there exists a hyperplane in the space of operators separating rhofrom S. Such a hyperplane defines uniquely a Hermitian operator W (observable) which has the following properties: The expectation value of W on all separable states, <W> ≥ 0, whereas its expectation value on ρ is negative, i.e. <W>ρ< 0.Figure 1Such an observable is for obvious reasons called entanglement witness, since it “detects” the entanglement of ρ. Every entangled state has its witnesses; the problem obviously is to find appropriate witnesses for a given state. To find out whether a given state is separable one should check whether its expectation value is non-negative for all witnesses. Obviously this is a necessary and sufficient separability criterion, but unfortunately it is not operational, in the sense that there is no simple procedure to test for all witnesses.Nevertheless, witnesses provide a very useful tool to study entanglement, especially if one has some knowledge about the state in question. They provide a sufficient entanglement condition, and may be obviously optimized (see Figure 2) by shifting the hyperplane in a parallel way towards S.Figure 2Bell inequalitiesAfter introducing the concept of separability and entanglement for mixed states, it is legitimate to ask what is the relation of mixed state entanglement and the existence of a LHV model, which requires that the state cannot violate any of the Bell-like inequalities. Let us discuss an example of such inequalities, the so called Clauser-Horne-Shimony- Holt inequality for two qubits. Let us assume that Alice and Bob measure two binary observables each, namely A 1, A 2, and B 1, B 2. The observables are random variables taking the values +1 or − 1, correlated possibly through some dependence on local hidden variables. It is easy to see that in the classical world, if B 1 + B 2 is zero, then B 1 − B 2 is either +2 or −2, and vice versa. Therefore if we define s = A 1(B 1 + B 2 ) + A 2 (B 1 − B 2 ) , we obtain that 2 ≥ s ≥ −2. This inequality holds also after averaging over various realizations. On the other hand, it can be shown that by taking suitable sets of observables for Alice and Bob we can find pure and even mixed quantum states that violate this inequality.Are Bell-like inequalities similar in this respect to witnesses, i.e. for a given entangled state can one always find a Bell-like inequality that “detects” it? The answer to this question is no, and has been already given by R. Werner in 1989. Even for two qubits there exist entangled states that admit an LHV model, i.e. cannot violate any Bell-like inequality.This observation indicates already that there is more structure in the “eggs” of Figure 1 and Figure 2. Separable states are evidently inside the PPT egg, according to the Peres condition. They admit an LHV model, i.e. they are also inside the LHV egg. But what about PPT entangled states? Do they violate some Bell-like inequality? Peres has formulated a conjecture that this not the case, and there is a lot of evidence that this conjecture is correct, although a rigorous proof is still missing.The distillability problem and bound entanglement Above we have classified quantum states according to the property of being either separable or entangled. An alternative classification approach is based on the possibility of distilling the entanglement of a given state. In a distillation protocol the entanglement of a given state is increased by performing local operations and classical communication on a set of identically prepared copies. In this way one obtains fewer, but “more entangled”, copies. This kind of technique was originally proposed in 1996 by Bennett and coworkers in the context of quantum teleportation, in order to achieve faithful transmission of quantum states over noisy channels. It also has applications in quantum cryptography as a method for quantum privacy amplification in entanglement based protocols in the presence of noise, as pointed out by David Deutsch and coworkers from Oxford.The distillability problem poses the question whether a given quantum state can be distilled or not. A separable state can never be distilled because the average entanglement of a set of states cannot be increased by local operations. Furthermore, the positivity of the partial transpose ensures that no distillation is possible. Thus, a given PPT entangled state is not distillable, and is therefore called bound entangled. There mayeven exist undistillable entangled states which do not have the PPT property. However, this conjecture is not proved at the moment.The first example of a PPT entangled state has been found by Pawel Horodecki from Gdansk in 1997. These states are so called edge states, which means that they cannot be written as a mixture of a separable state and a PPT entangled state. Particularly simple families of states have been suggested by Charles Bennett and coworkers at IBM, New York. They have found the so called unextendible product bases (UPB), i.e. sets of orthogonal product state-vectors, with the property that the space orthogonal to this set does not contain any product vector. It turns out that the projector onto this space is a PPT state, which obviously has to be entangled since it does not contain any product vector in its range (note that all state-vectors in the decomposition of a separable state ρinto a mixture of product states belong automatically to the range of ρ).The existence of bound entanglement is a mysterious invention of Nature. It is an interesting question to ask whether bound entanglement is a useful resource to perform quantum information processing tasks. It was shown so far that this is not the case for communication protocols such as quantum teleportation and quantum dense coding (i.e.a protocol that allows to enhance the transmission of classical information, using entanglement). However, surprisingly, it is possible to distill a secret key in quantum cryptography, starting from certain bound entangled states.Entanglement detectionAs discussed above, entanglement is a precious resource in quantum information processing. Typically in a real world experiment noise is always present and it leads to a decrease of entanglement in general. Thus, it is of fundamental interest for experimental applications to be able to test the entanglement properties of the generated states. A traditional method to this aim is represented by the Bell inequalities, a violation of which indicates the presence of entanglement. However, as mentioned above, not every entangled state violates a Bell inequality. So, not all entangled states can be detected by using this method.Another possibility is to perform complete state tomography, which allows determining all the elements of the density matrix. This is a useful method to get a complete knowledge of the density operator of a quantum system, but to detect entanglement it is an expensive process as it requires an unnecessary large number of measurements. If one has certain knowledge about the state the most appropriate technique is the measurement of the witness observable, which can be achieved by few local measurements. A negative expectation value clearly indicates the presence of entanglement.All these methods have been successfully implemented in various experiments. Recently another method for the detection of entanglement was suggested based on the physical approximation of the partial transpose. It remains a challenge to implement this idea in the laboratory because it requires the implementation of non local measurements.Entanglement measuresWhen classifying a quantum state as being entangled, a natural question is to quantify the amount of entanglement it contains. For pure quantum states there exists a well defined entanglement measure, namely the von Neumann entropy of the density operator of a subsystem of the composite state. For mixed states the situation is more complicated. There are several different possibilities to define an entanglement measure. The so called entanglement cost describes the amount of entanglement one needs in order to generate a given state. An alternative measure is the entanglement of formation, which is a more abstract definition. A further possibility to quantify entanglement is given by the minimum distance to separable states. Finally, motivated by physical applications, one can introduce the distillable entanglement which quantifies the extractable amount of entanglement.Unfortunately all of these quantities are very difficult to compute in general. For example, in order to determine the entanglement of formation one has to find the decomposition of the state that leads to the minimum average von Neumann entropy of a subsystem and this is a very challenging task. So far a complete analytical formula for the entanglement of formation only exists for composite systems of two qubits.Entanglement in multipartite systemsSo far, we have restricted ourselves to the case of composite systems with two subsystems, so called bipartite systems. When considering more than two parties, i.e multipartite systems, the situation becomes much more complex. For example, for the most simple tripartite case of three qubits, a pure state can be either completely separable, or biseparable (i.e. one of the three parties is not entangled with the other two), or genuinely entangled among all three parties. The latter class again consists of inequivalent subclasses, the so called GHZ and W states. This concept can be generalized to mixed states. For more than three parties it is easy to imagine that the number of subclasses grows fast.In recent years there has been much progress in the creation of multipartite entangled states in the laboratory. The existence of genuine multipartite entanglement has also been demonstrated experimentally by using the concept of witness operators.Even if the full classification of multipartite entanglement is a formidable task, certain classes of states, the so called graph states, have been completely characterized and shown to be useful both for quantum computational and quantum error correction protocols. Moreover, a deeper understanding of entanglement has proved to be very fruitful in connection with statistical properties of physical systems. All of these problems are discussed in more details in other sections of this publication.References[1] Einstein, P. Podolsky and N. Rosen, Phys. Rev. 47, 777 (1935)[2] J.S. Bell, Physics 1, 195 (1964)[3] P. Horodecki, Phys. Lett. A 232, 333 (1997)[4] M. Lewenstein et al., J. Mod. Opt. 47, 2481 (2000)[5] A. Peres, Phys. Rev. Lett. 77, 1413 (1996)[6] E. Schrödinger, Naturwissenschaften 23, 807 (1935)[7] R.F. Werner, Phys. Rev. A 40, 4277 (1989) Contact information of the author of this article Maciej LewensteinInstitut de Ciènces Fotòniques (ICFO)C/Jordi Girona 29, Nexus 2908034 BarcelonaSpainEmail: maciej.lewenstein@icfo.esChiara MacchiavelloIstituto Nazionale di Fisicadella Materia, Unita' di Pavia Dipartimento di Fisica "A. Volta"via Bassi 6I-27100 PaviaItalyEmail: chiara@unipv.itProf. Dr. Dagmar BrussInst. fuer Theoretische Physik IIIHeinrich-Heine-Universitaet Duesseldorf Universitaetsstr. 1, Geb. 25.32D-40225 Duesseldorf,GermanyEmail: bruss@thphy.uni-duesseldorf.de。
量子场论与高等量子力学的区别
量子场论与高等量子力学的区别Quantum field theory (QFT) and advanced quantum mechanics are two distinct branches of quantum physics, each with its own unique characteristics and applications. While both fields deal with the behavior of particles at the quantum level, they approach the subject from different angles and have distinct focuses. In this response, we will explore the differences between quantum field theory and advanced quantum mechanics from multiple perspectives.From a historical perspective, quantum mechanics was developed in the early 20th century as a framework to describe the behavior of individual particles, such as electrons and photons. It introduced concepts like wave-particle duality, quantization, and the uncertainty principle. Advanced quantum mechanics, also known as quantum mechanics beyond the introductory level, builds upon these foundational concepts and delves deeper into the mathematical formalism and applications of quantum theory.On the other hand, quantum field theory emerged in the late 1920s and early 1930s as an extension of quantum mechanics to incorporate the principles of special relativity. It treats particles as excitations of underlying fields that permeate all of spacetime. Unlike quantum mechanics, which focuses on individual particles, quantum field theory provides a framework for describing the interactions and dynamics of fields and particles in a relativistic manner.In terms of mathematical formalism, advanced quantum mechanics typically employs the Schrödinger equation or the Heisenberg picture to describe the time evolution of quantum systems. It utilizes wave functions or state vectors to represent the quantum states of particles and operators to describe observables. Quantum field theory, on the other hand, utilizes the framework of second quantization, which treats particles as quanta of field excitations. It employs field operators that create and annihilate particles and describes the state of a system using Fock space, which accounts for the presence of an arbitrary number of particles.Another key difference lies in the scope of application. Advanced quantum mechanics is often used to study systems with a small number of particles, such as atoms, molecules, and solid-state systems. It is particularly useful for understanding phenomena like quantum tunneling, energy quantization, and the behavior of particles in potential wells. Quantum field theory, on the other hand, isprimarily employed in the study of high-energy physics, where particle interactions occur at extremely small length scales and high energies. It is used to describe andpredict phenomena such as particle collisions, the behavior of elementary particles, and the creation and annihilationof particles.In summary, while both quantum field theory and advanced quantum mechanics are branches of quantum physics, they differ in their historical development, mathematical formalism, and scope of application. Quantum mechanics focuses on the behavior of individual particles and is applicable to systems with a small number of particles, while quantum field theory extends these principles toincorporate relativistic effects and describes the interactions of fields and particles in a relativistic manner, primarily in the realm of high-energy physics.。
大西洋月刊 美国名人100
《大西洋月刊》：美国历史上最有影响的100个名人1 Abraham LincolnHe saved the Union, freed the slaves, and presided over America’s second founding.2 George WashingtonHe made the United States possible—not only by defeating a king, but by declining to become one himself.3 Thomas JeffersonThe author of the five most important words in American history: “All men are created equal.”Louisiana purchaseEmbargo act of 1807Lewis and Clark expedition4 Franklin Delano RooseveltHe said, “The only thing we have to fear is fear itself,” and then he proved it.5 Alexander HamiltonSoldier, banker, and political scientist, he set in motion an agrarian nation’s transformation into an industrial power.6 Benjamin FranklinThe Founder-of-all-trades— scientist, printer, writer, diplomat, inventor, and more; like his country, he contained multitudes.7 John MarshallThe defining chief justice, he established the Supreme Court as the equal of the other two federal branches.8 Martin Luther King Jr.His dream of racial equality is still elusive, but no one did more to make it real.9 Thomas EdisonIt wasn’t just the lightbulb; the Wizard of Menlo Park was the most prolific inventor in American history.10 Woodrow WilsonHe made the world safe for U.S. interventionism, if not for democracy.11 John D. RockefellerThe man behind Standard Oil set the mold for our tycoons—first by making money, then by giving it away.12 Ulysses S. GrantHe was a poor president, but he was the general Lincoln needed; he also wrote the greatest political memoir in American history.13 James MadisonHe fathered the Constitution and wrote the Bill of Rights.14 Henry FordHe gave us the assembly line and the Model T, and sparked America’s love affair with the automobile.15 Theodore RooseveltWhether busting trusts or building canals, he embodied the “strenuous life” and blazed a trail for twentieth-century America.16 Mark TwainAuthor of our national epic, he was the most unsentimental observer of our national life.17 Ronald ReaganThe amiable architect of both the conservative realignment and the Cold War’s end.18 Andrew JacksonThe first great populist: he found America a republic and left it a democracy.19 Thomas PaineThe voice of the American Revolution, and our first great radical.20 Andrew CarnegieThe original self-made man forged America’s industrial might and became one of the nation’s greatest philanthropists.21 Harry TrumanAn accidental president, this machine politician ushered in the Atomic Age and then the Cold War.22 Walt WhitmanHe sang of America and shaped the country’s conception of itself.23 Wright BrothersThey got us all off the ground.24 Alexander Graham BellBy inventing the telephone, he opened the age of telecommunications and shrank the world.25 John AdamsHis leadership made the American Revolution possible; his devotion to republicanism made it succeed.26 Walt DisneyThe quintessential entertainer-entrepreneur, he wielded unmatched influence over our childhood.27 Eli WhitneyHis gin made cotton king and sustained an empire for slavery.28 Dwight EisenhowerHe won a war and two elections, and made everybody like Ike.29 Earl WarrenHis Supreme Court transformed American society and bequeathed to us the culture wars.30 Elizabeth Cady StantonOne of the first great American feminists, she fought for social reform and women’s right to vote.31 Henry ClayOne of America’s greatest legislators and orators, he forged compromises that held off civil war for decades.32 Albert EinsteinHis greatest scientific work was done in Europe, but his humanity earned him undying fame in America.33 Ralph Waldo EmersonThe bard of individualism, he relied on himself—and told us all to do the same.34 Jonas SalkHis vaccine for polio eradicated one of the world’s worst plagues.35 Jackie RobinsonHe broke baseball’s color barrier and embodied integration’s promise.36 William Jennings Bryan“The Great Commoner” lost three presidential elections, but his populism transformed the country.37 J. P. MorganThe great financier and banker was the prototype for all the Wall Street barons who followed.38 Susan B. AnthonyShe was the country’s most eloquent voice for women’s equality under the law.39 Rachel CarsonThe author of Silent Spring was godmother to the environmental movement.40 John DeweyHe sought to make the public school a training ground for democratic life.41 Harriet Beecher StoweHer Uncle Tom’s Cabin inspired a generation of abolitionists and set the stage for civil war.42 Eleanor RooseveltShe used the first lady’s office and the mass media to become “first lady of the world.”43 W. E. B. DuBoisOne of America’s great intellectuals, he made the “problem of the color line” his life’s wo rk.44 Lyndon Baines JohnsonHis brilliance gave us civil-rights laws; his stubbornness gave us Vietnam.45 Samuel F. B. MorseBefore the Internet, there was Morse code.46 William Lloyd GarrisonThrough his newspaper, The Liberator, he became the voice of abolition.47 Frederick DouglassAfter escaping from slavery, he pricked the nation’s conscience with an eloquent accounting of its crimes.48 Robert OppenheimerThe father of the atomic bomb and the regretful midwife of the nuclear era.49 Frederick Law OlmstedThe genius behind New York’s Central Park, he inspired the greening of America’s cities.50 James K. PolkThis one-term president’s Mexican War landgrab gave us California, Texas, and the Southwest.51 Margaret SangerThe ardent champion of birth control—and of the sexual freedom that came with it.52 Joseph SmithThe founder of Mormonism, America’s most famous homegrown faith.53 Oliver Wendell Holmes Jr.Known as “The Great Dissenter,” he wrote Supreme Court opinions that continue to shape American jurisprudence.54 Bill GatesThe Rockefeller of the Information Age, in business and philanthropy alike.55 John Quincy AdamsThe Monroe Doctrine’s real author, he set nineteenth-century America’s diplomatic course.56 Horace MannHis tireless advocacy of universal public schooling earned him the title “The Father of American Education.”57 Robert E. LeeHe was a good general but a better symbol, embodying conciliation in defeat.58 John C. CalhounThe voice of the antebellum South, he was slavery’s most ardent defender.59 Louis SullivanThe father of architectural modernism, he shaped the defining American building: the skyscraper.60 William FaulknerThe most gifted chronicler of America’s tormented and fascinating South.61 Samuel GompersThe country’s greatest labor organizer, he made the golden age of unions possible.62 William JamesThe mind behind Pragmatism, America’s most important philosophical school.63 George MarshallAs a general, he organized the American effort in World War II; as a statesman, he rebuilt Western Europe.64 Jane AddamsThe founder of Hull House, she became the secular saint of social work.65 Henry David ThoreauThe original American dropout, he has inspired seekers of authenticity for 150 years.66 Elvis PresleyThe king of rock and roll. Enough said.67 P. T. BarnumThe circus impresario’s taste for spectacle paved the way for blockbuster movies and reality TV.68 James D. WatsonHe codiscovered DNA’s double helix, revealing the code of life to scientists and entrepreneurs alike.69 James Gordon BennettAs the founding publisher of The New York Herald, he invented the modern American newspaper.70 Lewis and ClarkThey went west to explore, and millions followed in their wake.71 Noah WebsterHe di dn’t create American English, but his dictionary defined it.72 Sam WaltonHe promised us “Every Day Low Prices,” and we took him up on the offer.73 Cyrus McCormickHis mechanical reaper spelled the end of traditional farming, and the beginning of industrial agriculture.74 Brigham YoungWhat Joseph Smith founded, Young preserved, leading the Mormons to their promised land.75 George Herman “Babe” RuthHe saved the national pastime in the wake of the Black Sox scandal—and permanently linked sports and celebrity.76 Frank Lloyd WrightAmerica’s most significant architect, he was the archetype of the visionary artist at odds with capitalism.77 Betty FriedanShe spoke to the discontent of housewives everywhere—and inspired a revolution in gender roles.78 John BrownWhether a hero, a fanatic, or both, he provided the spark for the Civil War.79 Louis ArmstrongHis talent and charisma took jazz from the cathouses of Storyville to Broadway, television, and beyond.80 William Randolph HearstThe press baron who perfected yellow journalism and helped start the Spanish-American War.81 Margaret MeadWith Coming of Age in Samoa, she made anthropology relevant—andcontroversial.82 George GallupHe asked Americans what they thought, and the politicians listened.83 James Fenimore CooperThe novels are unreadable, but he was the first great mythologizer of the frontier.84 Thurgood MarshallAs a lawyer and a Supreme Court justice, he was the legal architect of the civil-rights revolution.85 Ernest HemingwayHis spare style defined American modernism, and his life made machismo a cliché.86 Mary Baker EddyShe got off her sickbed and founded Christian Science, which promised spiritual healing to all.87 Benjamin SpockWith a single book—and a singular approach—he changed American parenting.88 Enrico FermiA giant of physics, he helped develop quantum theory and was instrumental in building the atomic bomb.89 Walter LippmannThe last man who could swing an election with a newspaper column.90 Jonathan EdwardsForget the fire and brimstone: his subtle eloquence made him the country’s most influential theologian.91 Lyman BeecherHarriet Beecher Stowe’s clergyman father earned fame as an abolitionist and an evangelist.92 John SteinbeckAs the creator of Tom Joad, he chronicled Depression-era misery.93 Nat TurnerHe was the most successful rebel slave; his specter would stalk the white South for a century.94 George EastmanThe founder of Kodak democratized photography with his handy rolls of film.95 Sam GoldwynA producer for forty years, he was the first great Hollywood mogul.96 Ralph NaderHe made the cars we drive safer; thirty years later, he made George W. Bush the president.97 Stephen FosterAmerica’s first great songwriter, he brought us “O! Susanna” and “My Old Kentucky Home.”98 Booker T. WashingtonAs an educator and a champion of self-help, he tried to lead black America up from slavery.99 Richard NixonHe broke the New Deal majority, and then broke his presidency on a scandal that still haunts America.100 Herman MelvilleMoby Dick was a flop at the time, but Melville is remembered as the American Shakespeare.Arnold Schwarzenegger action movie actorKennedy 肯尼迪niece it is an evidence that he is a man with a strong political ambition Running for office 竞选公职Politician 政治人物California governor of a stateChief magistrate of districtCharismatic leadership 有魅力的领导Executive Charisma领袖魅力Energy and financial crisis 能源与财政危机Galileo GalileiPolitics itself is a kind of performance政治本身就是一种表演High-profile 有较高知名度的在一系列的“魔鬼”电影中，阿诺是一个仅能说“我将再来”、“再见！宝贝”或是“你被毁灭了”等简短台词、且说话带有强烈口音的肌肉男，扮演的是“魔鬼终结者”、“魔鬼毁灭者”、“最后魔鬼英雄”、“魔鬼司令”、及“终极战士”等阳刚十足的角色；在现实生活中，他是来自奥地利的移民，娶了美国前总统肯尼迪的外甥女，同时也是一位长期表达对政治有强烈企图心的名人。
原子物理与量子力学
原子物理与量子力学Atomic Physics and Quantum Mechanics哈尔滨理工大学应用科学学院应用物理系相关说明一、课程名称原子物理与量子力学二、计划学时108（每周3次6学时）三、课程性质技术基础课四、适用专业应用物理学、材料物理学、光信息科学与技术、电子科学与技术五、主要内容本课程内容主要可分为两大部分：1、原子物理学；2、量子力学。
原子物理学主要介绍原子物理学的发展。
从光谱学、X射线等方面的实验事实总结出能级规律，进一步分析原子结构的特点。
量子力学是二十世纪初建立起来的一门崭新的学科。
通过五个基本原理的引入，逐步构筑了量子力学的理论框架。
教学过程中，尽可能将两部分的相关内容结合讲授，利于学生理解和吸收。
原子物理学与量子力学是物理类学生的理论基础。
通过该课程的学习，学生应掌握有关原子等微观粒子的基本物理概念及反映其物理性质的基本规律，使学生了解和掌握现代一些重要的物理观念，并为应用技术准备理论基础。
六、教材与参考书《原子物理学》，褚圣麟，高教出版社《量子力学教程》，周世勋，高教出版社七、备注本课程采用多媒体教学，重点难点等采用特定的文字表现方式或动画声音等形式体现，可在“《原子物理与量子力学》课件”的相关章节观察效果。
目录绪论 (1)本章小结 (1)第一章原子的基本状况 (2)§1.1 原子的质量和大小 (2)§1.2 原子的核式结构 (2)本章小结 (3)第二章原子的能级和辐射 (4)§2.1 原子光谱的一般情况与氢原子光谱 (4)§2.2 经典理论的困难和光的波粒二象性 (4)§2.3 玻尔氢原子理论 (5)§2.4 类氢体系光谱 (5)§2.5 夫兰克-赫兹实验 (5)§2.6 量子化通则 (6)§2.7 电子的椭圆轨道 (6)§2.8 史特恩-盖拉赫实验与原子空间取向的量子化 (7)§2.9 量子理论与经典理论的对应关系对应原理 (7)本章小结 (7)第三章量子力学的运动方程—Schrödinger方程 (8)§3.1 物质的波粒二象性 (8)§3.2 波函数的统计解释 (8)§3.3 态叠加原理 (9)§3.4 薛定谔方程 (9)§3.5 几率守恒定律与定态薛定谔方程 (9)§3.6 一维无限深势阱 (10)§3.7 势垒贯穿 (10)§3.8 线性谐振子 (10)§3.9 电子在库仑场中的运动 (11)§3.10 氢原子 (11)本章小结 (12)第四章量子力学中的力学量 (13)§4.1 力学量算符 (13)§4.2 动量算符与角动量算符 (13)§4.3 厄密算符的本征函数 (14)§4.4 力学量的取值分布 (14)§4.5 算符的对易关系 (14)§4.6 测不准关系 (15)§4.7 守恒定律 (15)本章小结 (16)第五章碱金属原子的光谱和能级 (17)§5.1 碱金属原子的光谱和结构特点 (17)§5.2 碱金属原子光谱的精细结构 (17)§5.3 电子自旋与轨道运动的相互作用 (18)§5.4 单电子跃迁的选择定则 (18)*§5.5 氢原子光谱的精细结构与蓝姆移动 (18)本章小结 (19)第六章多电子原子 (20)§6.1 氦与第二族元素的光谱和能级 (20)§6.2 具有两个价电子的原子态 (20)§6.3 泡利原理与同科电子 (21)§6.4 复杂原子光谱的一般规律 (21)§6.5 辐射跃迁的普适选择定则 (21)§6.6 He-Ne激光器 (22)本章小结 (22)第七章磁场中的原子 (23)§7.1 原子的磁矩 (23)§7.2 外磁场对原子的作用 (23)§7.3 史特恩-盖拉赫实验的结果 (23)§7.4 顺磁共振 (24)*§7.5 物质的磁性 (24)§7.6 塞曼效应 (25)本章小结 (25)第八章原子的壳层结构 (26)§8.1 元素性质的周期性 (26)§8.2 原子的电子壳层结构 (26)§8.3 原子基态的电子组态 (26)本章小结 (27)第九章X射线 (28)§9.1 X射线的产生及测量 (28)§9.2 X射线的发射谱及相关能级 (28)*§9.3 X射线的吸收和散射 (28)*§9.4 X射线在晶体中的衍射 (29)本章小结 (29)第十章态和力学量的表象 (30)§10.1 态的表象 (30)§10.2 算符的矩阵表示 (30)§10.3 量子力学公式的矩阵表述 (31)§10.4 幺正变换 (31)§10.5 狄拉克符号 (31)§10.6 占有数表象 (32)本章小结 (32)第十一章微扰理论 (33)§11.1 非简并定态微扰理论及其应用 (33)§11.2 简并情况下的微扰理论及其应用 (33)§11.3 变分法与氦原子基态 (34)§11.4 与时间有关的微扰理论 (34)§11.5 跃迁几率 (34)§11.6 光的发射与吸收 (35)*§11.7 选择定则 (35)本章小结 (36)第十二章散射 (37)§12.1 碰撞过程与散射截面 (37)§12.2 中心力场中的弹性散射（分波法） (37)本章小结 (37)第十三章自旋与全同粒子 (39)§13.1 电子的自旋 (39)§13.2 电子自旋的描述 (39)§13.3 简单塞曼效应 (40)§13.4 角动量的耦合及应用 (40)§13.5 光谱的精细结构 (41)§13.6 全同粒子体系 (41)§13.7 全同粒子体系的波函数 (41)§13.8 两个电子的自旋函数 (42)本章小结 (42)绪论绪论本章主要介绍原子物理与量子力学的发展过程，并指出学习新理论应注意的问题。
量子力学英文读物
量子力学英文读物以下是一些关于量子力学的英文读物推荐：1. "Quantum: Einstein, Bohr, and the Great Debate about the Nature of Reality" by Manjit Kumar2. "The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory" by Brian Greene3. "The Quantum World: Quantum Physics for Everyone" by Kenneth W. Ford4. "Quantum Mechanics: Concepts and Applications" by Nouredine Zettili5. "Quantum Physics: A Beginner's Guide" by Alastair Rae6. "Quantum Computing for Computer Scientists" by Noson S. Yanofsky and Mirco A. Mannucci7. "Quantum Physics for Babies" by Chris Ferrie (a simplified introduction for children and adults)8. "The Strange World of Quantum Mechanics" by Daniel F. Styer这些书籍从不同的角度介绍了量子力学的基本原理、应用、历史以及相关的思想争论。
根据你的兴趣和程度，选择适合你的读物开始探索量子世界吧！。
假如尼尔斯来到我们的中间英语作文500字
全文分为作者个人简介和正文两个部分：作者个人简介：Hello everyone, I am an author dedicated to creating and sharing high-quality document templates. In this era of information overload, accurate and efficient communication has become especially important. I firmly believe that good communication can build bridges between people, playing an indispensable role in academia, career, and daily life. Therefore, I decided to invest my knowledge and skills into creating valuable documents to help people find inspiration and direction when needed.正文：假如尼尔斯来到我们的中间英语作文500字全文共3篇示例，供读者参考篇1If Niels Bohr Came Among UsOh my gosh, can you imagine if the great Niels Bohr just randomly showed up at our school one day? That would be absolutely crazy! Niels Bohr was this brilliant physicist fromDenmark who revolutionized our understanding of atomic structure and quantum theory back in the early 20th century. He's definitely one of the most important scientists who ever lived.I've been learning all about Bohr's atomic model in physics class. It was a huge breakthrough at the time. Before Bohr, scientists kind of just accepted the plum pudding model that J.J. Thomson proposed. Basically, Thomson thought the atom was a big blob of positive charge with negative electrons scattered throughout it, kind of like raisins in a plum pudding dessert. But that didn't really fit with experimental evidence.Then Niels Bohr came along and said, "Hold up, I have a better idea!" He proposed that the atom has a positive nucleus in the center, with negative electrons orbiting around it in specific shells or energy levels. It was kind of like a tiny solar system. This atomic structure model made so much more sense and could actually explain the spectrum of light emitted by hydrogen atoms.Another huge contribution from Bohr was founding the basis for understanding quantum theory. He figured out that electrons can only exist in those discrete energy levels or shells, not just anywhere. And when they jump between those levels,that's what causes atoms to absorb or emit light of specific wavelengths. Wild, right?Bohr was awarded the Nobel Prize in Physics in 1922 for his revolutionary atomic model and work on quantum mechanics. He deserved it 100%. His insights transformed physics forever. Can you imagine if he just randomly popped into our classroom during physics period? I would be starstruck for sure!I bet Niels Bohr would blow all of our minds with his genius intellect and passionate lectures. He was totally obsessed with physics and finding the fundamental laws of the universe. I could picture him at the front of our class, messily scribbling equations on the chalkboard with chalk dust flying everywhere as he tried to explain these mind-bending quantum phenomena.Of course, he would probably get frustrated that we're still beginners struggling to understand basic concepts like atomic orbitals and blackbody radiation. "You must be joking!" he might exclaim in his thick Danish accent as we stared blankly at yet another equation he derived from first principles. I'm sure the pace of a Bohr lecture would be absolutely dizzying.At the same time, I'll bet Bohr would be an incredibly patient and caring teacher. From what I've read, he cultivated this famous "Bohr spirit" of free expression and open debate in hisresearch team. He embraced different perspectives and encouraged creative thinking. So in our classroom, Bohr would probably be very nurturing and want each of us to feel comfortable asking questions or proposing ideas, even if they seemed a bit half-baked.I could totally see him putting on a fun little demonstration to illustrate quantum principles too. Maybe he would set up a light source and use prisms or diffraction slits to show us the wave-particle duality and quantization of light. Or he might do an experiment involving atomic spectroscopy to drive home the point about discrete energy levels. Knowing Bohr, it would likely involve pipes, cables, and vacuum tubes sprawled across the lab bench in a chaotic mess that only a genius could understand. But it sure would make atomic physics feel real and alive!Just interacting with someone of Bohr's intellectual caliber and pioneering spirit would be so valuable and inspiring, even if he talked way over our heads at times. This was a man who shaped humanity's understanding of the fundamental nature of matter and energy. He wasn't afraid to challenge the status quo and think in completely new ways. That courage and creativity in the face of the unknown is what drives scientific revolutions.Part of me wonders if we mere high school students could even begin to comprehend the insights and discoveries of a mind like Niels Bohr's. His contributions to quantum theory and models of atomic structure were so profound and consequential that they're still mind-boggling a century later. Having the chance to learn from and engage with him directly would be a tremendous opportunity that could change our perspective forever.At the same time, maybe Bohr's genius wouldn't seem so alienating up close and in person. From the photos and recordings I've seen, he came across as down-to-earth, approachable, and full of playful humor despite his brilliance. Sure, he would be operating on another level intellectually. But at his core, Bohr was simply a man fascinated by the deepest mysteries of the universe, just like we kids are fascinated by even the basics of how atoms and matter work.So if Niels Bohr suddenly appeared in our classroom, I think the overall vibe would be charged with awe and excitement. This giant of 20th century science walking among us? His very presence would lend immense weight and importance to our studies of quantum phenomena. At the same time, I'm sure Bohr's warmth, passion and unwavering scientific ideals wouldinspire us to approach physics with renewed vigor and confidence in our ability to one day understand the deepest truths of nature, just like he did. It would be an unforgettable experience that could spark a lifelong love of science and discovery in all of us. I really hope it happens someday!篇2If Niles Came to Our MidstWhoa, you guys will never believe what just happened! You know that super old book we had to read for English class, A Connecticut Yankee in King Arthur's Court by Mark Twain? Well, something crazy like that totally went down at school today!It all started during Mr. Henderson's history class. We were learning about the medieval period and going over all the crazy stuff people believed back then. You know, like how they thought the world was flat and that diseases were caused by bad smells? Dumb, right?Anyway, right in the middle of Mr. H's lecture, there was this huge boom of thunder that shook the whole classroom even though it was sunny outside. Then this blinding flash of light exploded right in the center of the room. When the spots clearedfrom my eyes, there was this dude standing there dressed in the weirdest getup I've ever seen.He had on these tight leggings with a puffy shirt and this long jacket thing that went down to his knees. And get this - he was wearing tights! On his head was this funny hat with a feather sticking out the side. I thought it was bad when my little brother went through that Shakespeare phase and wouldn't stop talking in ye olde English. This guy looked like he had gone all out at one of those medieval fairs.Of course, everyone started cracking up at his ridiculous outfit. A few of the football players started chanting "Shakespeare in the park! Shakespeare in the park!" I guess they thought he was promoting some school play or something.The guy just looked around at all of us like we were the crazy ones, which made everyone laugh even harder. Finally, Mr. Henderson got the class settled down and asked the guy who he was and what he was doing here.In this super deep voice that definitely didn't match his goofy costume, he announced, "I am Niles Kalcheim, a most learned engineer from the 24th century. An unforeseen dysfunction has materialized in my chrono-displacement moduleduring its trial run, projecting me backward through thespace-time continuum."I'm not gonna lie, half of what he said went completely over my head. All I caught was "24th century" and I thought maybe this was some sort of stupid prank where one of the AV club nerds was trying to play dress up as a time traveler or something.But then the dude - Niles, I guess - went and proved he really wasn't from around here. He pulled out this shiny rectangular thing from his pocket - which actually looked kinda like one of the smartphones we're finally allowed to have at school next year. Only this one didn't have a screen or buttons or anything. It was completely smooth on both sides.Niles must have done something to activate it though because all of a sudden it projected this hologram image that hung in the air in front of him! It looked just like one of those 3D projectors they use for video games and stuff, except whatever tech he was using was a million times better. The colors were brighter and more realistic than anything I've ever seen before.The hologram was of the most bizarre contraption I've ever laid eyes on. It looked like a jungle gym designed by an insane person, with all these twisting metal tubes and giant spheres interconnected in some nutso pattern. As the hologram slowlyrotated, more and more crazy details became visible and my mind was completely blown."This is a prototype for a molecular disassembler," Niles proclaimed, like that was supposed to mean something to those of us living in the modern age rather than the 24th century.He started rambling on about how this "disassembler" could break down any object on an atomic level and convert it into elemental components or just pure energy. He claimed with enough of these crazy machines, his century had unlimited recycling and could rearrange matter itself however they wanted!Even Mr. Henderson looked dumbfounded by all this super advanced science Niles was spewing out. I figured either this guy was legitimately insane or he really was some kind of visitor from the future.That's when Niles said the words that convinced me this wasn't just an elaborate prank: "Perhaps a demonstration would render my displacement more fathomable."Before anyone could stop him, he aimed that little shiny rectangle at Mr. Henderson's desk and some kind of energy beam shot out of it. The heavy wooden desk just...disappeared!Vanished into thin air like it had never existed! All that was left behind were little sparkling particles slowly wafting through the space the desk used to occupy before they faded away completely.You can imagine the chaos that erupted after that. The girls started screaming, a few guys nearly fainted, and pretty much everyone dove for cover like Niles was about to disintegrate us all next. Even Mr. Henderson looked terrified out of his mind, sprawled there on the floor clutching his teacher's edition like it could protect him from whatever power this madman possessed.For his part, Niles just watched everyone's freaked-out reactions with an expression that seemed more confused than threatening. He tried to tell us not to be afraid, that he meant no harm, but no one was listening at that point. A few seconds later, the room was swarmed by campus security rushing in to subdue the supposed lunatic.I'm not sure what happened to Niles after that. They might have hauled him off to jail - or maybe an insane asylum is more likely considering his crazy claims of being a time traveler. Either way, I'm just glad no one else got disintegrated or anything!Can you even imagine how mind blowing it would be if Niles was telling the truth? Like, think about all the insane things wecould have in our time if his future inventions were real! Unlimited energy, the ability to just rearrange atoms however we wanted...I don't think the world today is ready for that level of technological advancement. We'd probably just use it for stupid stuff like binge watching shows without worrying about electricity bills or creating endless amounts of junk food!Still, I can't stop thinking about what might be possible in the 24th century. Just the fact that Niles could travel hundreds of years through time is crazy enough. But being able to disassemble matter into its basic components with the push of a button? If that's for real, it makes you wonder what other miraculous technologies might exist in the future. Maybe they'll have figured out how to teleport between planets or have mastered human cloning or something. Heck, maybe they'll even have figured out how to go into suspended animation so you can just sleep for 300 years and wake up in the future!Whether Niles was an actual visitor from the 24th century or just a highly convincing loon, the whole experience has me looking at the world through a different lens. For so long, our history classes have been stuck looking backward - studying the primitive civilizations, the wars and power struggles of the past. But the truth is that the most important history hasn't happenedyet. The future is where the real game-changers are going to take place that'll make everything we know today look as outdated as those eurth-cultures we learned about carving wheels out of stone.Who knows what unbelievable wonders the 24th century might hold? Flying personal vehicles, artificial intelligence assistants, maybe even some kind of master computer network safeguarding the limitless knowledge of the future! What I wouldn't give for a peek at a history book from that era. I'll bet Niles' crazy desk-dematerializer barely even registers as a significant invention compared to whatever world-altering technologies are commonplace in his time.I just hope that whoever is in charge in the 24th century uses their insane science knowledge for good and not evil. Can you imagine someone like that Thanos guy from the Avengers movies getting his hands on Niles' molecular rearranging tech? He'd be able to disassemble entire planets with the push of a button! Not that we should be worrying about hypothetical supervillains from the future, I guess. We've got enough issues to deal with in the present without borrowing troubles from another millennium.Whew, okay, that's enough of me rambling about the metaphysics of technologies yet to be invented. Whether it was real or an illusion, having a so-called time traveler materialize out of nowhere in the middle of my history class was an experience I'll never forget. It's got me thinking bigger about what might be possible and has honestly made me a lot more excited to see what the future holds - even if it's just our current century rather than the reality-bending architectures of the 24th. We're living in a pivotal time where our wildest science fictions are slowly morphing into patentable realities.Who knows? Maybe a hundred years from now, people will look back and say the real game-changing invention was whatever allowed this written record to be preserved for their eyes to read - the first relic of a primitive篇3If Niels Came Among UsBy A StudentCan you imagine what it would be like if the great Danish physicist Niels Bohr just showed up at our school one day? I've thought about this a lot, and I think it would be totallymind-blowing!First of all, I'm sure nobody would even recognize him at first. He'd probably just look like some old dude with wild Einstein hair and a funny accent. But then once the science teachers figured out who he was, it would be pure pandemonium! They'd be freaking out trying to roll out the red carpet for one of the most important scientists of the 20th century.I can just picture Niels strolling down the hallway, looking totally confused at all the commotion surrounding him. He'd probably be like "What is this peculiar place? Why are all these young people carrying those strange flat objects?" And someone would have to explain to him that we're all students at a school in the 21st century, and those "flat objects" are laptop computers that we use to access vast repositories of human knowledge and dank memes.Once he got past the initial culture shock, I bet Niels would be lowkey blown away by how much science and technology has advanced since his day. A big part of his work was on quantum theory and atomic structure, which laid the foundations for all the crazy quantum computing, nanotechnology, and other cutting-edge fields we're just starting to explore now. He'd probably get a huge kick out of seeing kids coding quantumalgorithms or running atomic force microscope simulations on their laptops.At the same time, I think he'd also be lowkey disturbed by how we sometimes take science for granted or misuse it in problematic ways. Fromatingout of more fossil fuels to industrialized warfare to social media misinformation, I can imagine Niels shaking his head and lamenting how human folly always finds new ways to run amok despite our growing scientific knowledge. He seemed like a pretty philosophical and ethical guy from what I've read, so I bet he'd want to sit us all down for some real talk about using our smarts responsibly.But more than anything, I think having Niels here would totally reinvigorate how we think about and approach science. Too often, we treat it as this dead collection of facts and formulas that we just have to regurgitate onto tests and assignments. Having one of the OG scientific revolutionaries in our midst could breathe new life into it as this radical, living endeavor to constantly question, explore, and reshape our understanding of the universe. Niels literally helped overturn centuries of classical physics doctrine, so he could show us firsthand that science isn't about memorizing - it's about creative thinking, challenging orthodoxies, and pushing the boundaries of human knowledge.I'll never forget reading about Niels's famous quote that "An expert is a person who has found out by her own painful experience all the latest mistakes." To me, that just encapsulates the mindset of a true scientist. It's all about humbly admitting the limitations of our current knowledge, while boldly venturing into new intellectual frontiers and inevitably making new mistakes that eventually lead to new discoveries. That fearless, unorthodox spirit of curiosity is what Niels embodied, and what he could hopefully instill in all of us if he walked among us.Just having a real, flesh-and-blood scientific titan like that in the classroom, wowing us with his brilliance while also showing he was still just a humble, curious human being in search of truth - it would be incredibly inspiring. We're all so used to science being this abstract collection of dusty old books and online resources. But having Niels physically present would make it more visceral and real in a whole new way. We could ask him anything we wanted about his work, his life, his mindset, his experiences - and get answers straight from the source instead of through some detached, sterilized secondhand account.Maybe Niels could even take over and lead some classes for a while, either lecturing on the latest developments in physics while he was alive or even learning about and weighing in onbrand new 21st century concepts. Just being taught by one of the most innovative scientific minds in history instead of a normal teacher would be utterly fascinating. We could get his unique perspective on not just physics, but anything from global politics to the nature of human consciousness. With Niels at the helm, our science classes would become this free-flowing Socratic dialogue where the greatest questions of the cosmos are pondered and no knowledge is too sacred to scrutinize or update as we make new empirical discoveries.Ultimately, having Niels Bohr visit our school wouldn't just be a cool celebrity cameo - it could fundamentally reshape how we experience and think about science itself. No longer would it be this dead, academic pursuit where we just absorb information. It would become an ethos - a living, evolving way of seeing and questioning the world around us with wonder, humility, and fearless curiosity. We'd go from being passive receptacles for established theories to active participants in the never-ending process of exploring, revising, and adding to human knowledge through scientific inquiry.Just picturing Niels Bohr hanging out and sharing his perspectives and life experiences with us has me brimming with excitement. Listening to that pioneering voice - the voice thathelped spark a revolutionary leap in our understanding of the universe - could imbue us with a passion for constantly questioning, challenging, and advancing our scientific narratives. We'd be connected to that grand tradition of intellectual fearlessness that shows no law or dogma is too sacrosanct once the empirical evidence points a new way. The abstract would become flesh. The dead words on a page would breathe with the vitality of the living mind that gave birth to them.Having Niels Bohr walk among us would inject a jolt of life, meaning, and inspiration into how we experience science. We'd glimpse the soul behind the formulas. We'd make a personal connection with one of the great intellectual pioneers who showed us that the universe is an ever-evolving, ever-mysterious place that constantly demands we shed our blinders and seek new truths. Just sharing the same hallways with such a luminary presence could elevate all of our scientific pursuits from rote and tedious textbook repetition to a vibrant, radical mission to boldly meet the unknown and use our minds to unravel its deepest secrets. That's what science is really about - and having Niels Bohr here could finally make us feel that in our bones.。
量子力学英语词汇
.量子力学专业英语词汇1、microscopic world 微观世界2、macroscopic world 宏观世界3、quantum theory 量子[理]论4、quantum mechanics 量子力学5、wave mechanics 波动力学6、matrix mechanics 矩阵力学7、Planck constant 普朗克常数8、wave-particle duality 波粒二象性9、state 态10、state function 态函数11、state vector 态矢量12、superposition principle of state 态叠加原理13、orthogonal states 正交态14、antisymmetrical state 正交定理15、stationary state 对称态16、antisymmetrical state 反对称态17、stationary state 定态18、ground state 基态19、excited state 受激态20、binding state 束缚态21、unbound state 非束缚态22、degenerate state 简并态23、degenerate system 简并系24、non-deenerate state 非简并态25、non-degenerate system 非简并系26、de Broglie wave 德布罗意波27、wave function 波函数28、time-dependent wave function 含时波函数29、wave packet 波包30、probability 几率31、probability amplitude 几率幅32、probability density 几率密度33、quantum ensemble 量子系综34、wave equation 波动方程35、Schrodinger equation 薛定谔方程36、Potential well 势阱37、Potential barrien 势垒38、potential barrier penetration 势垒贯穿39、tunnel effect 隧道效应40、linear harmonic oscillator 线性谐振子41、zero proint energy 零点能.42、central field 辏力场43、Coulomb field 库仑场44、δ-function δ-函数45、operator 算符46、commuting operators 对易算符47、anticommuting operators 反对易算符48、complex conjugate operator 复共轭算符49、Hermitian conjugate operator 厄米共轭算符50、Hermitian operator 厄米算符51、momentum operator 动量算符52、energy operator 能量算符53、Hamiltonian operator 哈密顿算符54、angular momentum operator 角动量算符55、spin operator 自旋算符56、eigen value 本征值57、secular equation 久期方程58、observable 可观察量59、orthogonality 正交性60、completeness 完全性61、closure property 封闭性62、normalization 归一化63、orthonormalized functions 正交归一化函数64、quantum number 量子数65、principal quantum number 主量子数66、radial quantum number 径向量子数67、angular quantum number 角量子数68、magnetic quantum number 磁量子数69、uncertainty relation 测不准关系70、principle of complementarity 并协原理71、quantum Poisson bracket 量子泊松括号72、representation 表象73、coordinate representation 坐标表象74、momentum representation 动量表象75、energy representation 能量表象76、Schrodinger representation 薛定谔表象77、Heisenberg representation 海森伯表象78、interaction representation 相互作用表象79、occupation number representation 粒子数表象80、Dirac symbol 狄拉克符号81、ket vector 右矢量82、bra vector 左矢量83、basis vector 基矢量84、basis ket 基右矢85、basis bra 基左矢.86、orthogonal kets 正交右矢87、orthogonal bras 正交左矢88、symmetrical kets 对称右矢89、antisymmetrical kets 反对称右矢90、Hilbert space 希耳伯空间91、perturbation theory 微扰理论92、stationary perturbation theory 定态微扰论93、time-dependent perturbation theory 含时微扰论94、Wentzel-Kramers-Brillouin method W. K. B.近似法95、elastic scattering 弹性散射96、inelastic scattering 非弹性散射97、scattering cross-section 散射截面98、partial wave method 分波法99、Born approximation 玻恩近似法100、centre-of-mass coordinates 质心坐标系101、laboratory coordinates 实验室坐标系102、transition 跃迁103、dipole transition 偶极子跃迁104、selection rule 选择定则105、spin 自旋106、electron spin 电子自旋107、spin quantum number 自旋量子数108、spin wave function 自旋波函数109、coupling 耦合110、vector-coupling coefficient 矢量耦合系数111、many-particle system 多子体系112、exchange forece 交换力113、exchange energy 交换能114、Heitler-London approximation 海特勒-伦敦近似法115、Hartree-Fock equation 哈特里-福克方程116、self-consistent field 自洽场117、Thomas-Fermi equation 托马斯-费米方程118、second quantization 二次量子化119、identical particles 全同粒子120、Pauli matrices 泡利矩阵121、Pauli equation 泡利方程122、Pauli’s exclusion principle泡利不相容原理123、Relativistic wave equation 相对论性波动方程124、Klein-Gordon equation 克莱因-戈登方程125、Dirac equation 狄拉克方程126、Dirac hole theory 狄拉克空穴理论127、negative energy state 负能态128、negative probability 负几率129、microscopic causality 微观因果性.。
光线的研究 英语课文
光线的研究英语课文The history of light research, like optics and mechanics, was noticed in ancient Greece, and the law of light reflection was well known as early as Euclid's time. However, before the separation of natural science and religion, human understanding of the nature of light hardly made any progress, and only stayed at the level of understanding the forms of light transmission and application. In the 17th century, there were two kinds of voices about this problem: the wave theory and the particle theory.The Dutch physicist Huygens put forward the wave theory of light in his book "On Light" published in 1690, and deduced the law of reflection and refraction of light, which satisfactorily explained the reason why the speed of light decreased in dense medium, and at the same time explained the birefringence phenomenon when light entered ice.Newton, a British physicist, insisted on the theory of light particles. In his book Optics published in 1704, he proposed that light-emitting objects emit particles moving in a straight line, and the flow of particles hitting the retina will cause vision, which can also explain the refraction and reflection of light, and even the modification can explain thephenomenon of "diffraction" discovered by grimaldi.In 19th century, British physicist Maxwell introduced the concept of displacement current, established the basic equation of electromagnetism, and founded the electromagnetic theory of light. By proving that the speed of electric microwave propagating in vacuum is equal to the speed of light propagating in vacuum, it is deduced that light and electromagnetic wave are essentially the same, that is, light is an electromagnetic wave with a certain wavelength. In the 20th century, quantum theory and relativity were established one after another, and physics changed from classical physics to modern physics. In 1905, American physicist Einstein put forward the famous photoelectric effect.He believed that when ultraviolet rays irradiated the surface of an object, they would transfer energy to the surface electrons, so that they could get rid of the shackles of the nucleus and be released from the surface. Therefore, Einstein interpreted light as a collection of energy, photons. In 1925, the French physicist De Broglie put forward the theory that all substances have wave-particle duality, that is, all objects are both waves and particles. Then, several scientists, such as Planck, a famous German physicist, established the quantumphysics theory, which completely expanded human understanding of material properties. To sum up, the essence of light should be considered as "photon", which has wave-particle duality. Therefore, light is both a wave and a photon, but as a unique substance, its volatility still dominates. At the same time, light has dynamic mass, and its mass can be calculated according to Einstein's mass-energy equation.。
英文原版薛定谔科普
英文原版薛定谔科普Quantum mechanics, as proposed by Austrian physicist ErwinSchrödinger, is a fundamental theory in physics that describes the behavior of particles at the smallest scales. It provides a mathematical framework for understanding the wave-particle duality of matter and the probabilistic nature of physical interactions. Although quantum mechanics is widely considered to be one of the most successful theories in science, it is also one of the most perplexing and counterintuitive.量子力学是由奥地利物理学家薛定谔提出的一种基本理论，描述了粒子在最小尺度上的行为。
它为理解物质的波粒二象性和物理相互作用的概率性提供了数学框架。
虽然量子力学被广泛认为是科学中最成功的理论之一，但也是最令人困惑和反直觉的。
One of the fundamental principles of quantum mechanics is the superposition principle, which states that a system can exist in multiple states simultaneously until it is measured. This idea challenges our classical understanding of physical reality, where objects are expected to have definite properties at all times. Thefamous thought experiment known as Schrödinger's cat illustrates this concept, where a cat trapped in a box is considered both alive and dead until the box is opened and observed.量子力学的一个基本原理是叠加原理，它表明一个系统可以同时存在多个状态，直到被测量出来。
量子力学英文介绍
量子力学英文介绍Quantum mechanics, also known as quantum physics, is a branch of theoretical physics that describes the behavior of matter and energy at the smallest scales, including subatomic particles like electrons and photons. It is an incredibly complex and counterintuitive theory, but also one of the most successful scientific theories ever developed.Step 1: The Beginnings of Quantum MechanicsQuantum mechanics originated in the early 20th century, primarily through the work of physicists Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, and ErwinSchrödinger. Their investigations into the behavior of light and matter led them to develop a new set of mathematical equations that governed the behavior of subatomic particles.Step 2: The Weirdness of Quantum MechanicsQuantum mechanics has a number of strange and seemingly paradoxical features that make it hard to wrap one's head around. For example, particles at the quantum level do not have a definite location until they are measured, and they can exist in multiple states at once. Quantum mechanics also introduced the concept of entanglement, in which particles can become "entangled" so that a measurement of one particle can instantly affect the state of the other, even if they are separated by vast distances.Step 3: Applications of Quantum MechanicsDespite its weirdness, quantum mechanics has a wide range of practical applications. One of the most notable is the development of the transistor, which is a crucialcomponent in modern electronic devices like computers and smartphones. Quantum mechanics also plays a role in materials science, cryptography, and quantum computing, which has the potential to revolutionize computation.Step 4: Current Research in Quantum MechanicsQuantum mechanics continues to be an active area of research and discovery. Areas of current interest include quantum entanglement and teleportation, the development of more efficient quantum algorithms, and exploring the possibilities of quantum computing. Researchers are also investigating the relationship between quantum mechanics and general relativity, the other pillar of modern physics.In conclusion, quantum mechanics is a fascinating and important theory that has revolutionized our understanding of the universe. It has many practical applications and continues to inspire new discoveries and innovations. While its weirdness and complexity can be daunting, it is well worth the effort to understand and appreciate this amazing theory.。
Chapter14
Fig. 14-2 The curvature of space-time around a massive object, as predicted by general relativity, can be loosely pictured as the curvature on a rubber sheet caused by a heavy ball. Although this is only an analogy, it can help us to visualize many abstract concepts described by Einstein′s theory.
物质在强大的引力作用下被压缩到极度弯曲的空间中甚至连光也无法逃逸出来这个极度弯曲的时空区域称为黑洞blackhole
Chapter 14 Black holes
14.1 Newtonian picture Escape velocity: the minimum initial velocity needed to escape from a star Stronger gravity on the star′s surface larger escape velocity (more difficult to escape) Newton′s law of gravitation: the surface gravity is strong when the star is massive, or the star is small (inverse square law) If a star is massive and small
Fig. 14-5 The Kerr black hole consists of a rotating mass at the center, surrounded by two event horizons. The outer event horizon marks the boundary within which an observer cannot resist being dragged around the black hole with space-time. The inner event horizon marks the boundary within which nothing can escape.
量子力学英语
量子力学英语Quantum mechanics is a branch of physics that studies the behavior of matter and energy at the atomic and subatomic level. It is a relatively recent field, having been developed in the early 20th century by physicists such as Albert Einstein, Niels Bohr, Werner Heisenberg, and ErwinSchrödinger. The theory of quantum mechanics deals with the properties of particles and the way they interact, as well as the nature of waves and how they propagate through space.One of the fundamental principles of quantum mechanics is the wave-particle duality. This principle states that particles, such as electrons, can exhibit wave-like behavior, and waves, such as light, can exhibit particle-like behavior. This idea was first proposed by Louis de Broglie in 1924, and it has since been verified experimentally through various experiments.Another important concept in quantum mechanics is the uncertainty principle. This principle states that the more precisely the position of a particle is known, the less precisely its momentum can be measured. Similarly, the more precisely the momentum of a particle is known, the lessprecisely its position can be measured. The uncertainty principle is a result of the wave-particle duality and the fact that particles have both wave-like and particle-like properties.Quantum mechanics also introduces the idea of quantum states, which describe the properties of a particle or system of particles. These states are typically represented by wave functions, which are mathematical functions that describe the probability of finding a particle in a particular position or state. The wave function can also be used to predict the behavior of a particle or system of particles.One application of quantum mechanics is in the development of quantum computing. Unlike classical computing, which operates on bits that are either 0 or 1, quantum computing uses quantum bits, or qubits, which can be 0, 1, or both at the same time. This allows for the potential of exponentially faster computing speeds and the ability to solve problems that are too complex for classical computers.In conclusion, quantum mechanics is a fascinating branch of physics that has revolutionized the way we understand the behavior of matter and energy at the atomic and subatomic level. Its principles and concepts have practicalapplications in fields such as computing, cryptography, andquantum sensing, and continue to be a source of exploration and discovery for physicists today.。
二次量子化英文文献
二次量子化英文文献An Introduction to Second Quantization in Quantum Mechanics.Abstract: This article delves into the concept of second quantization, a fundamental tool in quantum field theory and many-body physics. We discuss its historical development, mathematical formalism, and applications in modern physics.1. Introduction.Quantum mechanics, since its inception in the early20th century, has revolutionized our understanding of matter and energy at the atomic and subatomic scales. One of the key concepts in quantum theory is quantization, the process of assigning discrete values to physical observables such as energy and momentum. While first quantization focuses on the quantization of individual particles, second quantization extends this principle tosystems of particles, allowing for a more comprehensive description of quantum phenomena.2. Historical Development.The concept of second quantization emerged in the late 1920s and early 1930s, primarily through the works of Paul Dirac, Werner Heisenberg, and others. It was a natural extension of the first quantization formalism, which had been successful in explaining the behavior of individual atoms and molecules. Second quantization provided a unified framework for describing both bosons and fermions, two distinct types of particles that exhibit different quantum statistical behaviors.3. Mathematical Formalism.In second quantization, particles are treated as excitations of an underlying quantum field. This approach introduces a new set of mathematical objects called field operators, which act on a Fock space – a generalization of the Hilbert space used in first quantization. Fock spaceaccounts for the possibility of having multiple particles in the same quantum state.The field operators, such as the creation and annihilation operators, allow us to represent particle creation and destruction processes quantum mechanically. These operators satisfy certain commutation or anticommutation relations depending on whether the particles are bosons or fermions.4. Applications of Second Quantization.Second quantization is particularly useful in studying systems with many particles, such as solids, gases, and quantum fields. It provides a convenient way to describe interactions between particles and the emergence of collective phenomena like superconductivity and superfluidity.In quantum field theory, second quantization serves as the starting point for perturbative expansions, allowing physicists to calculate the probabilities of particleinteractions and scattering processes. The theory has also found applications in particle physics, cosmology, and condensed matter physics.5. Conclusion.Second quantization represents a significant milestone in the development of quantum theory. It not only extends the principles of quantization to systems of particles but also provides a unified mathematical framework for describing a wide range of quantum phenomena. The impact of second quantization on modern physics is profound, and its applications continue to expand as we delve deeper into the quantum realm.This article has provided an overview of second quantization, its historical development, mathematical formalism, and applications in modern physics. The readeris encouraged to explore further the rich and fascinating world of quantum mechanics and quantum field theory.。
量子信息——连续变量篇
Quantum information with continuous variablesSamuel L.BraunsteinComputer Science,University of York,York YO105DD,United KingdomPeter van LoockNational Institute of Informatics(NII),Tokyo101-8430,Japan and Institute of TheoreticalPhysics,Institute of Optics,Information and Photonics(Max-Planck Forschungsgruppe),Universität Erlangen-Nürnberg,D-91058Erlangen,Germany͑Published29June2005͒Quantum information is a rapidly advancing area of interdisciplinary research.It may lead to real-world applications for communication and computation unavailable without the exploitation of quantum properties such as nonorthogonality or entanglement.This article reviews the progress in quantum information based on continuous quantum variables,with emphasis on quantum optical implementations in terms of the quadrature amplitudes of the electromagneticfield.CONTENTSI.Introduction513II.Continuous Variables in Quantum Optics516A.The quadratures of the quantizedfield516B.Phase-space representations518C.Gaussian states519D.Linear optics519E.Nonlinear optics520F.Polarization and spin representations522G.Necessity of phase reference523 III.Continuous-Variable Entanglement523A.Bipartite entanglement5251.Pure states5252.Mixed states and inseparability criteria526B.Multipartite entanglement5291.Discrete variables5292.Genuine multipartite entanglement5303.Separability properties of Gaussian states5304.Generating entanglement5315.Measuring entanglement533C.Bound entanglement534D.Nonlocality5341.Traditional EPR-type approach5352.Phase-space approach5363.Pseudospin approach536E.Verifying entanglement experimentally537 IV.Quantum Communication with Continuous Variables538A.Quantum teleportation5401.Teleportation protocol5412.Teleportation criteria5433.Entanglement swapping546B.Dense coding546rmation:A measure5472.Mutual information5473.Classical communication5474.Classical communication via quantum states5475.Dense coding548C.Quantum error correction550D.Quantum cryptography5501.Entanglement-based versus prepare andmeasure5502.Early ideas and recent progress5513.Absolute theoretical security5524.Verifying experimental security5535.Quantum secret sharing553E.Entanglement distillation554F.Quantum memory555V.Quantum Cloning with Continuous Variables555A.Local universal cloning5551.Beyond no-cloning5552.Universal cloners556B.Local cloning of Gaussian states5571.Fidelity bounds for Gaussian cloners5572.An optical cloning circuit for coherentstates558C.Telecloning559 VI.Quantum Computation with Continuous Variables560A.Universal quantum computation560B.Extension of the Gottesman-Knill theorem563 VII.Experiments with Continuous Quantum Variables565A.Generation of squeezed-state EPR entanglement5651.Broadband entanglement via opticalparametric amplification5652.Kerr effect and linear interference567B.Generation of long-lived atomic entanglement568C.Generation of genuine multipartite entanglement569D.Quantum teleportation of coherent states569E.Experimental dense coding570F.Experimental quantum key distribution571G.Demonstration of a quantum memory effect572 VIII.Concluding Remarks572 Acknowledgments573 References573I.INTRODUCTIONQuantum information is a relatively young branch of physics.One of its goals is to interpret the concepts of quantum physics from an information-theoretic point of view.This may lead to a deeper understanding of quan-REVIEWS OF MODERN PHYSICS,VOLUME77,APRIL20050034-6861/2005/77͑2͒/513͑65͒/$50.00©2005The American Physical Society513tum theory.Conversely,information and computation are intrinsically physical concepts,since they rely on physical systems in which information is stored and by means of which information is processed or transmitted. Hence physical concepts,and at a more fundamental level quantum physical concepts,must be incorporated in a theory of information and computation.Further-more,the exploitation of quantum effects may even prove beneficial for various kinds of information pro-cessing and communication.The most prominent ex-amples of this are quantum computation and quantum key distribution.Quantum computation means in par-ticular cases,in principle,computation faster than any known classical computation.Quantum key distribution makes possible,in principle,unconditionally secure communication as opposed to communication based on classical key distribution.From a conceptual point of view,it is illuminating to consider continuous quantum variables in quantum in-formation theory.This includes the extension of quan-tum communication protocols from discrete to continu-ous variables and hence fromfinite to infinite dimensions.For instance,the original discrete-variable quantum teleportation protocol for qubits and other finite-dimensional systems͑Bennett et al.,1993͒was soon after its publication translated into the continuous-variable setting͑Vaidman,1994͒.The main motivation for dealing with continuous variables in quantum infor-mation,however,originated in a more practical observa-tion:efficient implementation of the essential steps in quantum communication protocols,namely,preparing, unitarily manipulating,and measuring͑entangled͒quan-tum states,is achievable in quantum optics utilizing con-tinuous quadrature amplitudes of the quantized electro-magneticfield.For example,the tools for measuring a quadrature with near-unit efficiency or for displacing an optical mode in phase space are provided by homodyne-detection and feedforward techniques,respectively. Continuous-variable entanglement can be efficiently produced using squeezed light͓in which the squeezing of a quadrature’s quantumfluctuations is due to a non-linear optical interaction͑Walls and Milburn,1994͔͒and linear optics.A valuable feature of quantum optical implementa-tions based upon continuous variables,related to their high efficiency,is their unconditionalness.Quantum re-sources such as entangled states emerge from the non-linear optical interaction of a laser with a crystal͑supple-mented if necessary by some linear optics͒in an unconditional fashion,i.e.,every inverse bandwidth time.This unconditionalness is hard to obtain in discrete-variable qubit-based implementations using single-photon states.In that case,the desired prepara-tion due to the nonlinear optical interaction depends on particular͑coincidence͒measurement results ruling out the unwanted͑in particular,vacuum͒contributions in the outgoing state vector.However,the unconditional-ness of the continuous-variable implementations has its price:it is at the expense of the quality of the entangle-ment of the prepared states.This entanglement and hence any entanglement-based quantum protocol is al-ways imperfect,the degree of imperfection depending on the amount of squeezing of the laser light involved. Good quality and performance require large squeezing which is technologically demanding,but to a certain ex-tent͓about10dB͑Wu et al.,1986͔͒already state of the art.Of course,in continuous-variable protocols that do not rely on entanglement,for instance,coherent-state-based quantum key distribution,these imperfections do not occur.To summarize,in the most commonly used optical ap-proaches,the continuous-variable implementations al-ways work pretty well͑and hence efficiently and uncon-ditionally͒,but never perfectly.Their discrete-variable counterparts only work sometimes͑conditioned upon rare successful events͒,but they succeed,in principle, perfectly.A similar tradeoff occurs when optical quan-tum states are sent through noisy channels͑opticalfi-bers͒,for example,in a realistic quantum key distribu-tion scenario.Subject to losses,the continuous-variable states accumulate noise and emerge at the receiver as contaminated versions of the sender’s input states.The discrete-variable quantum information encoded in single-photon states is reliably conveyed for each photon that is not absorbed during transmission.Due to the recent results of Knill,Laflamme,and Mil-burn͑Knill et al.,2001͒,it is now known that efficient quantum information processing is possible,in principle, solely by means of linear optics.Their scheme is formu-lated in a discrete-variable setting in which the quantum information is encoded in single-photon states.Apart from entangled auxiliary photon states,generated off-line without restriction to linear optics,conditional dy-namics͑feedforward͒is the essential ingredient in mak-ing this approach work.Universal quantum gates such as a controlled-NOT gate can,in principle,be built using this scheme without need of any Kerr-type nonlinear op-tical interaction͑corresponding to an interaction Hamil-tonian quartic in the optical modes’annihilation and creation operators͒.This Kerr-type interaction would be hard to obtain on the level of single photons.However, the off-line generation of the complicated auxiliary states needed in the Knill-Laflamme-Milburn scheme seems impractical too.Similarly,in the continuous-variable setting,when it comes to more advanced quantum information proto-cols,such as universal quantum computation or,in a communication scenario,entanglement distillation,it turns out that tools more sophisticated than mere Gaussian operations are needed.In fact,the Gaussian operations are effectively those described by interaction Hamiltonians at most quadratic in the optical modes’annihilation and creation operators,thus leading to lin-ear input-output relations as in beam-splitter or squeez-ing transformations.Gaussian operations,mapping Gaussian states onto Gaussian states,also include ho-modyne detections and phase-space displacements.In contrast,the non-Gaussian operations required for ad-vanced continuous-variable quantum communication͑in particular,long-distance communication based on en-514S.L.Braunstein and P.van Loock:Quantum information with continuous variables Rev.Mod.Phys.,Vol.77,No.2,April2005tanglement distillation and swapping,quantum memory,and teleportation͒are due either to at least cubic non-linear optical interactions or to conditional transforma-tions depending on non-Gaussian measurements such asphoton counting.It seems that,at this very sophisticatedlevel,the difficulties and requirements of the discrete-and continuous-variable implementations are analogous.In this review,our aim is to highlight the strengths ofthe continuous-variable approaches to quantum infor-mation processing.Therefore we focus on those proto-cols that are based on Gaussian states and their feasiblemanipulation through Gaussian operations.This leads tocontinuous-variable proposals for the implementation ofthe simplest quantum communication protocols,such asquantum teleportation and quantum key distribution,and includes the efficient generation and detection ofcontinuous-variable entanglement.Before dealing with quantum communication andcomputation,in Sec.II,wefirst introduce continuousquantum variables within the framework of quantumoptics.The discussions about the quadratures of quan-tized electromagnetic modes,about phase-space repre-sentations,and about Gaussian states include the nota-tions and conventions that we use throughout thisarticle.We conclude Sec.II with a few remarks on linearand nonlinear optics,on alternative polarization andspin representations,and on the necessity of a phasereference in continuous-variable implementations.Thenotion of entanglement,indispensable in many quantumprotocols,is described in Sec.III in the context of con-tinuous variables.We discuss pure and mixed entangledstates,entanglement between two͑bipartite͒and be-tween many͑multipartite͒parties,and so-called bound ͑undistillable͒entanglement.The generation,measure-ment,and verification͑both theoretical and experimen-tal͒of continuous-variable entanglement are here of par-ticular interest.As for the properties of the continuous-variable entangled states related with theirinseparability,we explain how the nonlocal character ofthese states is revealed.This involves,for instance,vio-lations of Bell-type inequalities imposed by local real-ism.Such violations,however,cannot occur when themeasurements considered are exclusively of continuous-variable type.This is due to the strict positivity of theWigner function of the Gaussian continuous-variable en-tangled states,which allows for a hidden-variable de-scription in terms of the quadrature observables.In Sec.IV,we describe the conceptually and practi-cally most important quantum communication protocols formulated in terms of continuous variables and thus utilizing the continuous-variable͑entangled͒states. These schemes include quantum teleportation and en-tanglement swapping͑teleportation of entanglement͒, quantum͑super͒dense coding,quantum error correc-tion,quantum cryptography,and entanglement distilla-tion.Since quantum teleportation based on nonmaxi-mum continuous-variable entanglement,usingfinitely squeezed two-mode squeezed states,is always imperfect, teleportation criteria are needed both for the theoretical and for the experimental verification.As is known from classical communication,light,propagating at high speed and offering a broad range of different frequen-cies,is an ideal carrier for the transmission of informa-tion.This applies to quantum communication as well. However,light is less suited for the storage of informa-tion.In order to store quantum information,for in-stance,at the intermediate stations in a quantum re-peater,atoms are more appropriate media than light. Significantly,as another motivation to deal with continu-ous variables,a feasible light-atom interface can be built via free-space interaction of light with an atomic en-semble based on the alternative polarization and spin-type variables.No strong cavity QED coupling is needed as with single photons.The concepts of this transfer of quantum information from light to atoms and vice versa, as the essential ingredients of a quantum memory,are discussed in Sec.IV.FSection V is devoted to quantum cloning with con-tinuous variables.One of the most fundamental͑and historically one of thefirst͒“laws”of quantum informa-tion theory is the so-called no-cloning theorem͑Dieks, 1982;Wootters and Zurek,1982͒.It forbids the exact copying of arbitrary quantum states.However,arbitrary quantum states can be copied approximately,and the resemblance͑in mathematical terms,the overlap orfi-delity͒between the clones may attain an optimal value independent of the original states.Such optimal cloning can be accomplished locally by sending the original states͑together with some auxiliary system͒through a local unitary quantum circuit.Optimal cloning of Gauss-ian continuous-variable states appears to be more inter-esting than that of general continuous-variable states, because the latter can be mimicked by a simple coin toss.We describe a non-entanglement-based implemen-tation for the optimal local cloning of Gaussian continuous-variable states.In addition,for Gaussian continuous-variable states,an optical implementation exists of optimal cloning at a distance͑telecloning͒.In this case,the optimality requires entanglement.The cor-responding multiparty entanglement is again producible with nonlinear optics͑squeezed light͒and linear optics ͑beam splitters͒.Quantum computation over continuous variables,dis-cussed in Sec.VI,is a more subtle issue than the in some sense straightforward continuous-variable extensions of quantum communication protocols.Atfirst sight,con-tinuous variables do not appear well suited for the pro-cessing of digital information in a computation.On the other hand,a continuous-variable quantum state having an infinite-dimensional spectrum of eigenstates contains a vast amount of quantum information.Hence it might be promising to adjust the continuous-variable states theoretically to the task of computation͑for instance,by discretization͒and yet to exploit their continuous-variable character experimentally in efficient͑optical͒implementations.We explain in Sec.VI why universal quantum computation over continuous variables re-quires Hamiltonians at least cubic in the position and momentum͑quadrature͒operators.Similarly,any quan-tum circuit that consists exclusively of unitary gates from515S.L.Braunstein and P.van Loock:Quantum information with continuous variables Rev.Mod.Phys.,Vol.77,No.2,April2005the continuous-variable Clifford group can be efficientlysimulated by purely classical means.This is acontinuous-variable extension of the discrete-variableGottesman-Knill theorem in which the Clifford groupelements include gates such as the Hadamard͑in thecontinuous-variable case,Fourier͒transform or the con-trolled NOT͑CNOT͒.The theorem applies,for example,to quantum teleportation which is fully describable by CNOT’s and Hadamard͑or Fourier͒transforms of some eigenstates supplemented by measurements in thateigenbasis and spin or phaseflip operations͑or phase-space displacements͒.Before some concluding remarks in Sec.VIII,wepresent some of the experimental approaches to squeez-ing of light and squeezed-state entanglement generationin Sec.VII.A.Both quadratic and quartic optical nonlin-earities are suitable for this,namely,parametric downconversion and the Kerr effect,respectively.Quantumteleportation experiments that have been performed al-ready based on continuous-variable squeezed-state en-tanglement are described in Sec.VII.D.In Sec.VII,wefurther discuss experiments with long-lived atomic en-tanglement,with genuine multipartite entanglement ofoptical modes,experimental dense coding,experimentalquantum key distribution,and the demonstration of aquantum memory effect.II.CONTINUOUS VARIABLES IN QUANTUM OPTICSFor the transition from classical to quantum mechan-ics,the position and momentum observables of the par-ticles turn into noncommuting Hermitian operators inthe Hamiltonian.In quantum optics,the quantized elec-tromagnetic modes correspond to quantum harmonicoscillators.The modes’quadratures play the roles of theoscillators’position and momentum operators obeyingan analogous Heisenberg uncertainty relation.A.The quadratures of the quantizedfieldFrom the Hamiltonian of a quantum harmonic oscil-lator expressed in terms of͑dimensionless͒creation and annihilation operators and representing a single mode k, Hˆk=បk͑aˆk†aˆk+12͒,we obtain the well-known form writ-ten in terms of“position”and“momentum”operators ͑unit mass͒,Hˆk=12͑pˆk2+k2xˆk2͒,͑1͒withaˆk=1ͱ2បk͑k xˆk+ipˆk͒,͑2͒aˆk†=1ͱ2បk͑k xˆk−ipˆk͒,͑3͒or,conversely,xˆk=ͱប2k͑aˆk+aˆk†͒,͑4͒pˆk=−iͱបk2͑aˆk−aˆk†͒.͑5͒Here,we have used the well-known commutation rela-tion for position and momentum,͓xˆk,pˆkЈ͔=iប␦kkЈ,͑6͒which is consistent with the bosonic commutation rela-tions͓aˆk,aˆkЈ†͔=␦kkЈ,͓aˆk,aˆkЈ͔=0.In Eq.͑2͒,we see that up to normalization factors the position and the momentum are the real and imaginary parts of the annihilation op-erator.Let us now define the dimensionless pair of con-jugate variables,Xˆkϵͱk2បxˆk=Re aˆk,Pˆkϵ1ͱ2បk pˆk=Im aˆk.͑7͒Their commutation relation is then͓Xˆk,PˆkЈ͔=i2␦kkЈ.͑8͒In other words,the dimensionless position and momen-tum operators,Xˆk and Pˆk,are defined as if we setប=1/2.These operators represent the quadratures of a single mode k,in classical terms corresponding to the real and imaginary parts of the oscillator’s complex am-plitude.In the following,by using͑Xˆ,Pˆ͒or equivalently ͑xˆ,pˆ͒,we shall always refer to these dimensionless quadratures as playing the roles of position and momen-tum.Hence͑xˆ,pˆ͒will also stand for a conjugate pair of dimensionless quadratures.The Heisenberg uncertainty relation,expressed in terms of the variances of two arbitrary noncommuting observables Aˆand Bˆfor an arbitrary given quantum state,͗͑⌬Aˆ͒2͘ϵŠ͑Aˆ−͗Aˆ͒͘2‹=͗Aˆ2͘−͗Aˆ͘2,͗͑⌬Bˆ͒2͘ϵŠ͑Bˆ−͗Bˆ͒͘2‹=͗Bˆ2͘−͗Bˆ͘2,͑9͒becomes͗͑⌬Aˆ͒2͗͑͘⌬Bˆ͒2͘ജ14͉͓͗Aˆ,Bˆ͔͉͘2.͑10͒Inserting Eq.͑8͒into Eq.͑10͒yields the uncertainty re-lation for a pair of conjugate quadrature observables of a single mode k,xˆk=͑aˆk+aˆk†͒/2,pˆk=͑aˆk−aˆk†͒/2i,͑11͒namely,͗͑⌬xˆk͒2͗͑͘⌬pˆk͒2͘ജ14͉͓͗xˆk,pˆk͔͉͘2=116.͑12͒Thus,in our units,the quadrature variance for a vacuum or coherent state of a single mode is1/4.Let us further516S.L.Braunstein and P.van Loock:Quantum information with continuous variables Rev.Mod.Phys.,Vol.77,No.2,April2005illuminate the meaning of the quadratures by looking at a single frequency mode of the electric field ͑for a single polarization ͒,E ˆk ͑r ,t ͒=E 0͓a ˆk ei ͑k ·r −k t ͒+a ˆk †e −i ͑k ·r −k t ͔͒.͑13͒The constant E 0contains all the dimensional prefactors.By using Eq.͑11͒,we can rewrite the mode asE ˆk ͑r ,t ͒=2E 0͓x ˆk cos ͑k t −k ·r ͒+pˆk sin ͑k t −k ·r ͔͒.͑14͒Clearly,the position and momentum operators xˆk and p ˆk represent the in-phase and out-of-phase components of the electric-field amplitude of the single mode k with respect to a ͑classical ͒reference wave ϰcos ͑k t −k ·r ͒.The choice of the phase of this wave is arbitrary,of course,and a more general reference wave would lead us to the single-mode descriptionE ˆk ͑r ,t ͒=2E 0͓x ˆk ͑⌰͒cos ͑k t −k ·r −⌰͒+pˆk ͑⌰͒sin ͑k t −k ·r −⌰͔͒,͑15͒with the more general quadraturesxˆk ͑⌰͒=͑a ˆk e −i ⌰+a ˆk †e +i ⌰͒/2,͑16͒p ˆk ͑⌰͒=͑a ˆk e −i ⌰−a ˆk †e +i ⌰͒/2i .͑17͒These new quadratures can be obtained from x ˆk and p ˆk via the rotationͩx ˆk ͑⌰͒pˆk ͑⌰͒ͪ=ͩcos ⌰sin ⌰−sin ⌰cos ⌰ͪͩxˆk pˆk ͪ.͑18͒Since this is a unitary transformation,we again end upwith a pair of conjugate observables fulfilling the com-mutation relation ͑8͒.Furthermore,because pˆk ͑⌰͒=x ˆk ͑⌰+/2͒,the whole continuum of quadratures is cov-ered by x ˆk ͑⌰͒with ⌰͓0,͒.This continuum of observ-ables is indeed measurable by relatively simple means.Such a so-called homodyne detection works as follows.A photodetector measuring an electromagnetic mode converts the photons into electrons and hence into an electric current,called the photocurrent i ˆ.It is therefore sensible to assume i ˆϰn ˆ=a ˆ†a ˆor i ˆ=qaˆ†a ˆwhere q is a con-stant ͑Paul,1995͒.In order to detect a quadrature of themode aˆ,the mode must be combined with an intense local oscillator at a 50:50beam splitter.The local oscil-lator is assumed to be in a coherent state with large photon number,͉␣LO ͘.It is therefore reasonable to de-scribe this oscillator by a classical complex amplitude␣LO rather than by an annihilation operator aˆLO .The two output modes of the beam splitter,͑aˆLO +a ˆ͒/ͱ2and ͑a ˆLO −a ˆ͒/ͱ2͑see Sec.II.D ͒,may then be approximated byaˆ1=͑␣LO +a ˆ͒/ͱ2,aˆ2=͑␣LO −a ˆ͒/ͱ2.͑19͒This yields the photocurrentsi ˆ1=qa ˆ1†aˆ1=q ͑␣LO *+a ˆ†͒͑␣LO +a ˆ͒/2,i ˆ2=qa ˆ2†aˆ2=q ͑␣LO *−a ˆ†͒͑␣LO −a ˆ͒/2.͑20͒The actual quantity to be measured will be the differ-ence photocurrent␦i ˆϵi ˆ1−i ˆ2=q ͑␣LO *aˆ+␣LO a ˆ†͒.͑21͒By introducing the phase ⌰of the local oscillator,␣LO=͉␣LO ͉exp ͑i ⌰͒,we recognize that the quadrature observ-able xˆ͑⌰͒from Eq.͑16͒is measured ͑without mode index k ͒.Now adjustment of the local oscillator’s phase ⌰͓0,͔enables us to detect any quadrature from thewhole continuum of quadratures xˆ͑⌰͒.A possible way to realize quantum tomography ͑Leonhardt,1997͒,i.e.,the reconstruction of the mode’s quantum state given by its Wigner function,relies on this measurement method,called ͑balanced ͒homodyne detection .A broadband rather than a single-mode description of homodyne de-tection can be found in the work of Braunstein and Crouch ͑1991͒,who also investigate the influence of a quantized local oscillator.We have now seen that it is not too hard to measure the quadratures of an electromagnetic mode.Unitary transformations such as quadrature displacements ͑phase-space displacements ͒can also be relatively easily performed via the so-called feedforward technique,as opposed to,for example,photon number displacements.This simplicity and the high efficiency when measuring and manipulating continuous quadratures are the main reasons why continuous-variable schemes appear more attractive than those based on discrete variables such as the photon number.In the following,we shall refer mainly to the conju-gate pair of quadratures xˆk and p ˆk ͑position and momen-tum,i.e.,⌰=0and ⌰=/2͒.In terms of these quadra-tures,the number operator becomesn ˆk =a ˆk †a ˆk =x ˆk 2+p ˆk 2−12,͑22͒using Eq.͑8͒.Let us finally review some useful formulas for the single-mode quadrature eigenstates,xˆ͉x ͘=x ͉x ͘,pˆ͉p ͘=p ͉p ͘,͑23͒where we have now dropped the mode index k .They are orthogonal,͗x ͉x Ј͘=␦͑x −x Ј͒,͗p ͉p Ј͘=␦͑p −p Ј͒,͑24͒and complete,͵−ϱϱ͉x ͗͘x ͉dx =1,͵−ϱϱ͉p ͗͘p ͉dp =1.͑25͒Just as for position and momentum eigenstates,the quadrature eigenstates are mutually related to each other by a Fourier transformation,͉x ͘=1ͱ͵−ϱϱe −2ixp ͉p ͘dp ,͑26͒517S.L.Braunstein and P .van Loock:Quantum information with continuous variablesRev.Mod.Phys.,Vol.77,No.2,April 2005͉p͘=1ͱ͵−ϱϱe+2ixp͉x͘dx.͑27͒Despite being unphysical and not square integrable,the quadrature eigenstates can be very useful in calculations involving the wave functions͑x͒=͗x͉͘,etc.,and inidealized quantum communication protocols based on continuous variables.For instance,a vacuum state infi-nitely squeezed in position may be expressed by a zero-position eigenstate͉x=0͘=͉͐p͘dp/ͱ.The physical,fi-nitely squeezed states are characterized by the quadrature probability distributions͉͑x͉͒2,etc.,ofwhich the widths correspond to the quadrature uncer-tainties.B.Phase-space representationsThe Wigner function is particularly suitable as a “quantum phase-space distribution”for describing the effects on the quadrature observables that may arise from quantum theory and classical statistics.It behaves partly as a classical probability distribution,thus en-abling us to calculate measurable quantities such as mean values and variances of the quadratures in a classical-like fashion.On the other hand,in contrast to a classical probability distribution,the Wigner function can become negative.The Wigner function was originally proposed by Wigner in his1932paper“On the quantum correction for thermodynamic equilibrium”͑Wigner,1932͒.There, he gave an expression for the Wigner function in terms of the position basis which reads͑with x and p being a dimensionless pair of quadratures in our units withប=1/2as introduced in the previous section;Wigner, 1932͒W͑x,p͒=2͵dye+4iyp͗x−y͉ˆ͉x+y͘.͑28͒Here and throughout,unless otherwise specified,the in-tegration will be over the entire space of the integration variable͑i.e.,here the integration goes from−ϱtoϱ͒. We gave Wigner’s original formula for only one mode or one particle͓Wigner’s͑1932͒original equation was in N-particle form͔because it simplifies the understanding of the concept behind the Wigner function approach. The extension to N modes is straightforward.Why does W͑x,p͒resemble a classical-like probability distribution?The most important attributes that explain this are the proper normalization,͵W͑␣͒d2␣=1,͑29͒the property of yielding the correct marginal distribu-tions,͵W͑x,p͒dx=͗p͉ˆ͉p͘,͵W͑x,p͒dp=͗x͉ˆ͉x͘,͑30͒and the equivalence to a probability distribution in clas-sical averaging when mean values of a certain class of operators Aˆin a quantum stateˆare to be calculated,͗Aˆ͘=Tr͑ˆAˆ͒=͵W͑␣͒A͑␣͒d2␣,͑31͒with a function A͑␣͒related to the operator Aˆ.The measure of integration is in our case d2␣=d͑Re␣͒d͑Im␣͒=dxdp with W͑␣=x+ip͒ϵW͑x,p͒,and we shall use d2␣and dxdp interchangeably.The opera-tor Aˆrepresents a particular class of functions of aˆand aˆ†or xˆand pˆ.The marginal distribution for p,͗p͉ˆ͉p͘,is obtained by changing the integration variables͑x−y =u,x+y=v͒and using Eq.͑26͒,that for x,͗x͉ˆ͉x͘,by using͐exp͑+4iyp͒dp=͑/2͒␦͑y͒.The normalization of the Wigner function then follows from Tr͑ˆ͒=1.For any symmetrized operator͑Leonhardt,1997͒,the so-called Weyl correspondence͑Weyl,1950͒,Tr͓ˆS͑xˆn pˆm͔͒=͵W͑x,p͒x n p m dxdp,͑32͒provides a rule for calculating quantum-mechanical ex-pectation values in a classical-like fashion according to Eq.͑31͒.Here,S͑xˆn pˆm͒indicates symmetrization.For example,S͑xˆ2pˆ͒=͑xˆ2pˆ+xˆpˆxˆ+pˆxˆ2͒/3corresponds to x2p ͑Leonhardt,1997͒.Such a classical-like formulation of quantum optics in terms of quasiprobability distributions is not unique.In fact,there is a whole family of distributions P͑␣,s͒of which each member corresponds to a particular value of a real parameter s,P͑␣,s͒=12͵͑,s͒exp͑i␣*+i*␣͒d2,͑33͒with the s-parametrized characteristic functions ͑,s͒=Tr͓ˆexp͑−iaˆ†−i*aˆ͔͒exp͑s͉͉2/2͒.͑34͒The mean values of operators normally and antinor-mally ordered in aˆand aˆ†may be calculated via the so-called P function͑s=1͒and Q function͑s=−1͒,re-spectively.The Wigner function͑s=0͒and its character-istic function͑,0͒are perfectly suited to provide ex-pectation values of quantities symmetric in aˆand aˆ†such as the quadratures.Hence the Wigner function,though not always positive definite,appears to be a good com-promise in describing quantum states in terms of quan-tum phase-space variables such as single-mode quadra-tures.We may formulate various quantum states relevant to continuous-variable quantum communica-tion by means of the Wigner representation.These par-ticular quantum states exhibit extremely nonclassical features such as entanglement and nonlocality.Yet their Wigner functions are positive definite,and thus belong to the class of Gaussian states.518S.L.Braunstein and P.van Loock:Quantum information with continuous variables Rev.Mod.Phys.,Vol.77,No.2,April2005。
2024年高考英语复习讲练测(新教材新高考)阅读理解细节理解题(原卷版)
第1讲阅读理解细节理解题（模拟精练+真题演练）根据文章选择正确的选项1.(2023年河北衡水中学模拟预测A篇)Big Thinkers SeriesThe2022Big Thinkers Series from New Scientist events features four online talks,covering a wide range of topics by world-class scientist speakers and experts.If you are curious about your planet or your universe,then this series is your place to hear the latest research.Save£20off the standard ticket price by purchasing a series ticket to all four talks in the Big Thinkers Series(available on-demand)or purchase single tickets for just£13per lecture(available by early booking).Reality+:From the Matrix to the Metaverse with David ChalmersIn this talk,philosopher David Chalmers argues that Metaverse-style virtual worlds experienced through headsets are also genuine and meaningful realities and we can live a meaningful life in VR.What we don’t know about gravity with Claudia de RhamWe are all familiar with the concept of gravity.In this talk,Professor Claudia de Rham will explore how much we actually know about gravity and how much more there is left to uncover.A Brief History of Timekeeping with Chad OrzelFrom Stonehenge to atomic clocks,here is the5,000-year history of how science is used to mark time.Chad Orzel,the internationally bestselling author of How to Teach Quantum Physics to Your Dog,offers us a witty journey through scientific theory and quirky(反常的)historical detail.Physics at the End of the universe with Katie MackThe Big Bang theory tells the story of the beginning of the universe for the last13.8billion years.But how does the story end?Join astronomer Katie Mack as she shares what modern astrophysics tells us about the final fate of the universe.1．How much does a series ticket cost?A．£13.B．£20.C．£30.D．£32.2．What will Chad Orzel lecture in?A．The genuine reality.B．The secrets of gravity.C．The history of time marking.D．The final fate of the universe.3．What do the four talks have in common?A．They are all aimed at science lovers.B．They are all concerned with gravity. C．They will all be given by bestselling authors.D．They will all be given by excellent physicians.2.(2023年河北衡水中学模拟预测B篇)Helga Stentzel’s Clothesline Animals combine charming images as fine art prints in various sizes.As an artist whose style she calls“household surrealism(超现实主义)”，she works in various media and has a large collection of works.Instead of throwing an old pair of pants or T-shirt away,Helga Stentzel puts her tired garments out to the farm.By hanging them on a simple clothesline she sets up and folding them artfully that look like animals,she takes wonderful pictures.Some are shot in real locations while others are digitally placed in environments in charming form with appealing colors.4．How did Stentzel create an artwork according to paragraph2?A．By designing clothes on software.B．By painting animals in various colors.C．By taking photos of animals on the farm.D．By hanging clothes folded in animal shapes.3.(2023年浙江金华一中联考二模）“Anyone knows single parents who can’t afford to get their child’s hair done for school?I will braid(编辫子)it for free!”Brittany Starks wrote on a Facebook post.She decided to offer her hair braiding services after a family friend delivered backpacks full of school supplies,clothing and shoes for Cayden and Ceniyah in early August.“At the time,I didn’t have anything for my kids to start school,”said Starks,who is in between homes and staying with her mother.“It meant so much to me.”What got Brittany Starks to offer her hair braiding service?A．A post on Facebook.B．Her friend’s timely help.C．Her mother’s advice.D．A trip to her kids’school.4.（2023年湖北华中师大一附中模拟预测）HobbitonUnlike the other locations in this list,the Shire is a wholly artificial set,built on a sheep farm on New Zealand‘s North Island.Created for Peter Jackson’s big-screen adaptation of J.R.R. Tolkien’s The Lord of the Rings trilogy,Hobbiton began to draw curious fans shortly after therelease of the first film in the series.In time,what began as a temporary location designed to host a three-month movie shoot has evolved into a Tolkienesque theme park with over350,000visitors annually.Which of the four locations should you visit if you are a big fan of J.R.R.Tolkien?A．Mars(The Martian).B．Jurassic Park.C．Hobbiton.D．King’s Landing.5.（（2023年湖北华中师大一附中模拟预测）I truly believe we all have a very special purpose in life,regardless of who we are or where we come from.After ten years of working for a major Wall Street bank,I wanted to do something challenging.So when I read a Merrill Lynch advertisement looking to hire more stockbrokers(股票经纪人),with great excitement,I made some phone calls and arranged to meet with one of its branch vice presidents.After this interview and interviews with twelve of his top stockbrokers,I eventually landed the job.The first few months was a struggle.I lived on very little commission(佣金).Night after night,I left the office weary and exhausted,ready to give up,yet somehow returning the next morning to start anew day.Eventually,all the hard work paid off.In less than four years,I became one of the top sales people at my branch and increased personal sales by1,700percent.The success earned me a six-figure income,promotion and numerous sales awards.46．Why did the author meet with a Merrill Lynch branch vice president?A．To arrange an interview.B．To make an advertisement.C．To employ more clerks.D．To get a position.6.（2023届湖北省襄阳四中模拟试题）A Wild Child's Guide to Endangered AnimalsFrom New York Times bestselling author Millie Marotta comes this gorgeous celebration of the animal kingdom.Highlighting43endangered species,the book takes readers on a trip around the world while learning about rare and well-known animals and their habitats.MarcovaldoMarcovaldo is a collection of20short stories written by Italo Calvino.Describing the life of a poor rural man living in northern Italy,the stories unfold according to the seasonal cycle of a mon themes in the stories include pollution,failure and poverty.The Art of MondoOver the years,Mondo has received global recognition for its incredible art posters that bring to life classic films,television shows,and comics such as Jurassic Park.For the first time,The Art of Mondo brings together this highly sought-after art in one volume that showcases the incredible creativity of the studio's artists whose vastly different styles are united by one guiding principle:limitless passion for their subject matters.The Coming of the Third ReichThere is no story in20th-century history more important to understand than Hitler's rise to power and the collapse(坍塌)of civilization in Nazi Germany.The Coming of the Third Reich,by Richard Evans,offers a masterful combination of academic work,important new research and interpretations.Patriarchy and CapitalismChizuko Ueno,a leading Japanese sociologist,feminist critic and public intellectual,has been a pioneer in women's studies and the author of many books,including Patriarchy and Capitalism. 50．Which book will you choose if you are interested in art?A．Marcovaldo.B．The Art of Mondo.C．The Coming of the Third Reich.D．Patriarchy and Capitalism.51．Who cares about women's rights and interests?A．Millie Marotta.B．Italo Calvino.C．Richard Evans.D．Chizuko Ueno.7.（2023年湖南长沙雅礼中学二模）Known on social media as The Sioux Chef,Sean Sherman grew up on the Pine Ridge Indian Reservation.He is reconnecting the locals of North America with native flavors and ingredients, and working to inspire a generation of indigenous(本土的)chefs to reclaim their cooking past.Pine Ridge in South Dakota contains some of the poorest communities in the country,and it’s out of that environment that Sherman got his first job in the restaurant industry as a dishwasher at a local steakhouse.As he developed a love of cooking,which saw him move to Minneapolis to study Japanese and French cuisines,Sherman realized he didn’t know indigenous recipes.“What were my Lakota ancestors eating and storing away?How were they getting oils,salts and fats and things like that?”Sherman remembered asking himself in an interview on PBS NewsHour.“So it took me quite a few years of just researching,but it really became a passion.”These years of researching,talking to elders,and consulting written material helped him produce The Sioux Chefs Indigenous Kitchen,which in2018won Sherman the James Beard Award for Best American Cookbook.After publishing the book,Sherman opened his restaurant,Owamni,in Minneapolis and created the North American Traditional Indigenous Food Systems(NATIFS).It is a professional indigenous kitchen and training center that seeks to create an educational space for native chefs to be trained and develop their skills,and reconnect with their cooking heritage.“Part of our challenge to ourselves was to cut out ingredients that are not native so we stopped using dairy,wheat flour and cane sugar,”he said.He cooks with local ingredients.His choices of meats are the same as those hunted by his ancestors—deer,fish,and birds.“For indigenous people who went through very strong assimilation(同化现象),we lost a lot of our food culture,”Sherman said.“But we’re at a point now where we can reclaim it and develop it for the next generation.To be able to share culture through food will be really healing.”64．What did Sherman realize when he was in Minneapolis?A．He didn’t have enough cooking passion.B．He should spend a few years researching cooking.C．He should write a book about the indigenous recipes.D．He didn’t know his Lakota ancestors’cooking ways and ingredients.65．Sherman set up the NATIFS center to________.A．make money and open his own restaurantB．build an educational space for local childrenC．train and help local chefs to cook local foodD．teach native chefs the most superb cooking skills66．What is a problem for his native cooking culture according to Sherman?A．Very strong assimilation.B．Its high speed of evolution.C．Too much meat in the diet.D．Indigenous recipes that can’t be shared.8.（2023年广东华南师大附中模拟预测）Check out what’s coming soon and what’s in development.Playbill will update these listings when new information is made available.THE COLLABORATION at Samuel J.Friedman TheatreThe play tells a true story in New York.Fifty-six-year-old Warhol’s star is falling.Jean is the new wonder-kid taking the art world by storm.When Jean agrees to work together with Warhol on a new exhibition,it soon becomes the talk of the city.The two artists set foot on a shared journey, both artistic and deeply personal,which redraws both their worlds.ALMOST FAMOUS at Bernard B．Jacobs TheatreBased on the film of the same name in2000,the musical features Pulitzer winner Kitt and a book by Crowe,who earned an Oscar award for writing the original film based on his own teenage experience.The coming-of-age story tracks a15-year-old music fan named William who follows the emerging band Stillwater on tour.THE PIANO LESSON at Ethel Barrymnore TheatreThe play is the fourth in Wilson’s Century Cycl,which digs into the Black experience in every decade of the20th century.Set in Pittsburgh’s Hill District in1936,it centers around a brother and a sister involved in a battle over a piano carved with the faces of their ancestors.KIMBERLY AKIMBO at Booth TheatreKim is a bright and funny high school girl,who happens to look like a72-year-old lady.And yet her aging disease may be the least of her problems.Forced to deal with family secrets,and possible crime charges,Kim is determined to explore happiness in a world where not even time is on her side.68．What kind of play is THE COLLABORATION?A．A romance.B．A life story.C．A fairy tale.D．A sci-fi story. 69．Which theatre should you visit if you want to learn about racial issues?A．Samuel J.Friedman Theatre.B．Bernard B．Jacobs Theatre.C．Ethel Barrymore Theatre.D．Booth Theatre.9.（2023届福建省厦门一中高三下学期二模试题）I have lived in rural America for nine years,first in Michigan,where I got my PhD;then in central Illinois and now in Indiana,where I am a professor.In a place where most people have lived the whole of their lives,I feel like a stranger.There are few things I enjoy more than complaining about my geographic isolation.I’m a vegetarian,so there’s nowhere to go for a nice dinner that isn’t50miles away.I’m black,so there’s nowhere to get my hair done that doesn’t involve another50-mile drive.And the closest major airport is two hours away.What causes the author’s loneliness?A．Dietary habits.B．Racial prejudice.C．Educational differences.D．Identity confusion.10.（2023届江苏南京市盐城市第二次调研试题）In southeastern Brazil,local fishers walk into dark waters in search of mullet(鲻鱼)On their own,it would be tricky to find the silvery fish.But the humans get help from an unusual partner: wild bottlenose dolphins.With nets in hand,the fishers patiently wait as their cetacean(鲸类的)partners drive the fish toward the shore.A signal from the dolphins—usually a deep dive—indicates when they should cast their nets.This fishing partnership has passed down through the generations,lasting for more than a century.24．What do the first two paragraphs talk about concerning Brazilian fishers?A．They trick dolphins into fishing for them.B．They harvest more fish with dolphins'help.C．They have been training dolphins over a century.D．They cast the fishing nets when dolphins surface.11.（2023届江苏省苏州八校联盟高三二模检测试题）Master Gardener Volunteers WantedWhy Become a Master Gardener?The Master Gardener program is an all-volunteer organization where you can develop your own leadership and teaching skills while teaching the younger youth about healthy eating, agriculture,and so on!Master Gardeners involve people in activities to improve their general well-being and overall enjoyment of life by helping them find sound management practices for home and urban natural resources,by creating pleasing environments through people-plant interactions and horticultural therapy(园艺疗法),and by contributing to a safe,abundant food supply through home fruit and vegetable production.What Qualifications Must You Meet?Anyone can apply to be a Master Gardener—you don’t need to be an expert or have a degree. You do,however,need to:●Have certain experience or know a little about gardening or landscape management.●Be willing to share horticulture information with others.●Be willing to attend a training program and can devote time to volunteering and continuing education.Besides,to become a Master Gardener volunteer,each applicant needs to complete an application,prepare background screening paperwork and schedule an interview with Extension staff.What Does the Training Involve?Training sessions are offered one day a week over a three-month period and are led by expert educators in the region.Approximately60hours of classroom instruction and field study and60 hours of volunteer internship(实习)work are required to complete the program and become certified.In order to remain a certified Master Gardener,30hours of volunteer work and10hours of continuing education or advanced training are required each year1．What does a Master Gardener do?A．Help raise people’s quality of life by horticulture.B．Teach the youth about diets and agriculture.C．Promote horticultural practices at home.D．Train volunteers to help with gardening.2．What is required if you want to apply to be a Master Gardener?A．Acquiring excellent teaching skills.B．Having some relevant knowledge.C．Completing given training sessions.D．Obtaining rich volunteer experience.12.（2023届湖南省九校联盟第二次联考英语试题）Are you fond of watching films?Does the colorful,natural,or spectacular scenery in the films attract you to travel to their locations?We have selected three gorgeous film locations in China.If you’re a film fan or an outdoor enthusiast,check them out!Fengguo Temple＆The Grandmaster(《一代宗师》)Located in Y’xian county,Jinzhou,Northeast China’s Liaoning province,the Fengguo Temple is a Buddhist temple established in1020,covering a total area of60,000square meters.It is one of only three Liao Dynasty temples still in existence in China.The main hall of the Fengguo Temple is the Buddha hall believed to be one of the largest in the world in ancient times.It is home to the world’s oldest and largest clay sculptures of painted Buddha statues.The Fengguo Temple was designated(指定)as a national foremost protected cultural heritage site in1961and a4A-level tourist attraction in2009.Yunshuiyao Ancient Town＆The Knot(《云水谣》)Situated in Zhangzhou,East China’s Fujian province,Yunshuiyao Ancient Town has a long history and is one of the scenic spots of the world heritage site,the Fujian Tulou.There is a magnificent banyan tree(榕树)group in the town consisting of13banyan trees,some of which are thousands of years old.Yunshuiyao Ancient Town is distinguished for its unique tulou clusters at the foot of the mountain.Fifty-three of these earthen buildings,which were first constructed in the mid Yuan Dynasty,are still standing today.Dajiu Lake Wetland Park＆The Assassin(《刺客聂隐娘》)Located in Shennongjia UNESCO Global Geopark,Central China’s Hubei province,the Dajiu Lake Wetland Park boasts fascinating sceneries.It is a rare subalpine peat marsh wetland in the world’s middle latitude,at an altitude of over1,730meters and with a total area of20,000 hectares.Known as“Hulun Buir of Hubei province”,it is home to nine lakes on the plateau and lush meadows(草地).In the wetland park,there are extensive alpine meadows,wetland ferns(蕨类植物),and some animals,such as storks,cranes,and sika deer,which are valuable for scientific research.1．What is special about Fengguo Temple?A．Its main hall is considered the largest in the world.B．It was designated as a4A-level tourist attraction in1961.C．It is one of only three Buddhist temples in existence in China.D．It houses the world’s oldest and largest clay sculptures of painted Buddha statues. 2．What can we know from the text?A．There are13banyan trees in Yunshuiyao Ancient Town. B．There are unique earthen buildings in Yunshuiyao Ancient Town. C．The Dajiu Lake Wetland Park is on the UNESCO World Heritage List. D．The Dajiu Lake Wetland Park is home to many rare plants and animals.Travel Writing·Starting date:24th April,2023·Duration:8weeks·Time:6:30pm to9:00pm·Occurs:Monday·Fees:£355•Location:OnlineCourse overviewIn this writing for travel course you will learn how to evoke(唤起)a sense of place,structure your story,and how travel writers connect with the travel industry to get“hospitality”.Who is it for?This course is aimed at those with some writing experience who want to develop their ideas for travel writing.It also suits photographers looking to add words to their pictures and bloggers looking to engage more readers.This course is not suitable for those who wish to improve their English.1．How long is the total class hours?A．24hours.B．20hours.C．8hours.D．2.5hours.15.（2023届江苏新高考基地高三4月大联考）It took Schultz a year to convince the Starbucks owners to hire him.When they finally made him director of marketing and operations in1982,he had another idea.This one occurred in Italy, when Schultz noticed the coffee bars that existed on almost every block.He learned that they not only served excellent espressos(蒸馏咖啡),they also served as meeting places or public squares, and there were200,000of them in the country.But when he came back to Seattle,the Starbucks owners resisted Schultz’s plans to serve coffee in the stores,saying the restaurant business was competitive,and it was costly to hire waiters.After all,economic benefits were their primary motivator.Frustrated,Schultz quit and started his own coffee-bar business in1985,named“II Giornale”.It was successful,and two years later,the original Starbucks management sold its Starbucks retail unit to Schultz for$3.8million.As the company began to expand rapidly in the1990s,Schultz always said that the main goal was“to serve a great cup of coffee”.Asked about the secret of his success,Schultz told us the principles:“Don’t be threatened by people smarter than promise anything but your core values.”24．What caused Schultz to join the Starbucks?A．The pleasant smell of its coffee bean.B．His strong desire to improve himself. C．The owners’impressive work attitude.D．His eagerness to sell more coffeemakers. 25．Which of the following can best describe Schultz’s personality?A．Committed and generous.B．Sociable and helpful.C．Motivated and considerate.D．Determined and creative.26．Why did the Starbucks owners refuse to serve coffee in the stores?A．Many coffee bars had existed in Seattle.B．People preferred tasting coffee at home.C．Workforce was insufficient in the market.D．They tried to avoid high cost of labor force.27．What does Schultz think contributes to his success?A．Learning from smarter people.B．Sticking to his own core values. C．Keeping his business a secret.D．Remembering a set of principles.根据文章选出正确的选项1.（2023年新高考I卷A篇）PricesHand Brake,Three Gears Foot Brake,No Gears1hour€7.50€5.003hours€11.00€7.501day(24hours)€14.75€9.75Each additional day€8.00€6.002.How much do you pay for renting a bike with hand brake and three gears for two days?A.€15.75.B.€19.50.C.€22.75.D.€29.50.2.（2023年新高考I卷B篇）......The task John set for himself was to remove harmful substances from some sludge(污泥). First,he constructed a series of clear fiberglass tanks connected to each other.Then he went around to local ponds and streams and brought back some plants and animals.He placed them in the tanks and waited.Little by little,these different kinds of life got used to one another and formed their own ecosystem.After a few weeks,John added the sludge.He was amazed at the results.The plants and animals in the eco-machine took the sludge as food and began to eat it!Within weeks,it had all been digested,and all that was left was pure water.Over the years,John has taken on many big jobs.He developed a greenhouse-like facilitythat treated sewage(污水)from1,600homes in South Burlington.He also designed aneco-machine to clean canal water in Fuzhou,a city in southeast China.“Ecological design”is the name John gives to what he does.“Life on Earth is kind of a box of spare parts for the inventor,”he says.“You put organisms in new relationships and observe what’s happening.Then you let these new systems develop their own ways to self-repair.”5.Why did John put the sludge into the tanks?A.To feed the animals.B.To build an ecosystem.C.To protect the plants.D.To test the eco-machine.3.（2023年新高考I卷C篇）The goal of this book is to make the case for digital minimalism,including a detailed exploration of what it asks and why it works,and then to teach you how to adopt this philosophy if you decide it’s right for you.8.What is the book aimed at?A.Teaching critical thinking skills.B.Advocating a simple digital lifestyle.C.Solving philosophical problems.D.Promoting the use of a digital device.4.(2023年新高考I卷D篇)On March7,1907,the English statistician Francis Galton published a paper which illustrated what has come to be known as the“wisdom of crowds”effect.The experiment of estimation he conducted showed that in some cases,the average of a large number of independent estimates could be quite accurate.This effect capitalizes on the fact that when people make errors,those errors aren’t always the same.Some people will tend to overestimate,and some to underestimate.When enough of these errors are averaged together,they cancel each other out,resulting in a more accurate estimate.If people are similar and tend to make the same errors,then their errors won’t cancel each other out.In more technical terms,the wisdom of crowds requires that people’s estimates be independent.If for whatever reasons,people’s errors become correlated or dependent,the accuracy of the estimate will go down.But a new study led by Joaquin Navajas offered an interesting twist(转折)on this classic phenomenon.The key finding of the study was that when crowds were further divided into smaller groups that were allowed to have a discussion,the averages from these groups were more accurate than those from an equal number of independent individuals.For instance,the average obtained from the estimates of four discussion groups of five was significantly more accurate than the average obtained from20independent individuals.13.Navajas’study found that the average accuracy could increase even if________.A.the crowds were relatively smallB.there were occasional underestimatesC.individuals did not communicateD.estimates were not fully independent5.（2023年新高考II卷A篇）Yellowstone National Park offers a variety of ranger programs throughout the park,and throughout the year.The following are descriptions of the ranger programs this summer.Experiencing Wildlife in Yellowstone(May26to September2)Whether you’re hiking a backcountry trail(小径),camping,or just enjoying the park’s amazing wildlife from the road,this quick workshop is for you and your family.Learn where to look for animals and how to safely enjoy your wildlife watching experience.Meet at the Canyon Village Store.Junior Ranger Wildlife Olympics(June5to August21)Kids can test their skills and compare their abilities to the animals of Yellowstone.Stay for as little or as long as your plans allow.Meet in front of the Visitor Education Center.Canyon Talks at Artist Point(June9to September2)From a classic viewpoint,enjoy Lower Falls,the Yellowstone River,and the breathtaking colors of the canyon(峡谷)while learning about the area’s natural and human history.Discover why artists and photographers continue to be drawn to this special place.Meet on the lower platform at Artist Point on the South Rim Drive for this short talk.Photography Workshops(June19&July10)Enhance your photography skills—join Yellowstone’s park photographer for a hands-on program to inspire new and creative ways of enjoying the beauty and wonder of Yellowstone.6/19—Waterfalls&Wide Angles:meet at Artist Point.7/10—Wildflowers&White Balance:meet at Washburn Trailhead in Chittenden parking area.2.What is the short talk at Artist Point about?A.Works of famous artists.B.Protection of wild animals.C.Basic photography skills.D.History of the canyon area.3.Where will the participants meet for the July10photography workshop?A.Artist Point.B.Washburn Trailhead.C.Canyon Village Store.D.Visitor Education Center.6.（2023年新高考II卷B篇）Turning soil,pulling weeds,and harvesting cabbage sound like tough work for middle and high school kids.And at first it is,says Abby Jaramillo,who with another teacher started Urban Sprouts,a school garden program at four low-income schools.The program aims to help students develop science skills,environmental awareness,and healthy lifestyles.4.What do we know about Abby Jaramillo?A.She used to be a health worker.B.She grew up in a low-income family.C.She owns a fast food restaurant.D.She is an initiator of Urban Sprouts.7.（2023年新高考II卷C篇）In this“book of books,”artworks are selected and arranged in a way that emphasizes these connections between different eras and cultures.We see scenes of children learning to read at home or at school,with the book as a focus for relations between the generations.Adults are。
英文原版量子论科普
英文原版量子论科普全文共四篇示例，供读者参考第一篇示例：One of the key principles of quantum mechanics is the concept of superposition. This principle states that particles can exist in multiple states at the same time. For example, an electron can be in a state of both spin up and spin down simultaneously. This is in contrast to classical mechanics, where particles are assumed to have definite positions and properties at all times.第二篇示例：The development of quantum mechanics began in the early 20th century with the work of physicists such as Max Planck, Albert Einstein, and Niels Bohr. One of the key insights of quantum mechanics is that particles such as electrons and photons can exhibit both particle-like and wave-like behavior. This wave-particle duality is a central feature of quantum mechanics and has important implications for the behavior of particles at the quantum level.第三篇示例：Quantum mechanics, also known as quantum physics or quantum theory, is a fundamental theory in physics that describes the behavior of matter and energy at the smallest scales of atoms and subatomic particles. It is a branch of physics that deals with the behavior of matter and energy on the scale of atomic and subatomic particles.第四篇示例：Quantum mechanics, a branch of physics that involves the study of the behavior of particles at the smallest scales, has often been described as one of the most mysterious and counterintuitive theories in science. This is because it challenges our classical understanding of the physical world, introducing concepts such as superposition, entanglement, andwave-particle duality.。
Quantum Mechanics
Quantum MechanicsQuantum mechanics is a fundamental theory in physics that describes the behavior of matter and energy at the atomic and subatomic levels. It has revolutionized our understanding of the universe, challenging our classical intuition and providing a framework for understanding phenomena such as the behavior of particles at the quantum level, the wave-particle duality, and quantum entanglement. This theory has had a profound impact on various fields, including chemistry, material science, and technology, and continues to be a subject of intense research and debate. The development of quantum mechanics can be traced back to the early 20th century, with the pioneering work of physicists such as Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, and Erwin Schr?dinger. Planck's discovery of quantized energy levels in blackbody radiation andEinstein's explanation of the photoelectric effect were early indications that classical physics was insufficient to describe the behavior of particles at the atomic scale. Bohr's model of the atom, with quantized electron orbits, and Heisenberg's uncertainty principle further challenged classical notions of determinism and causality. Schr?dinger's wave equation provided a mathematical framework for describing the wave-like behavior of particles, leading to the development of quantum mechanics as a formal theory. The historical development of quantum mechanics was marked by intense debates and differing perspectives among physicists. The Copenhagen interpretation, proposed by Bohr and Heisenberg, emphasized the role of observation and measurement in collapsing the wave function and determining the state of a particle. This interpretation led to the concept of wave function collapse and the probabilistic nature of quantum phenomena. However, alternative interpretations, such as the many-worlds interpretation and the pilot-wave theory, have been proposed to reconcile the apparent paradoxes and philosophical implications of quantum mechanics. One of the most famous examples illustrating the peculiarities of quantum mechanics is the thought experiment known as "Schrodinger's cat." In this scenario, a cat is placed in a sealed box with a device that has a 50% chance of releasing poison based on the decay of a radioactive atom. According to quantum mechanics, until the box is opened and the cat is observed, the cat is considered to be both alive and dead, existing in asuperposition of states. This illustrates the concept of superposition and therole of observation in determining the state of a quantum system. Theimplications of quantum mechanics have been far-reaching, with both benefits and drawbacks. On the one hand, quantum mechanics has led to the development of technologies such as lasers, transistors, and MRI machines, revolutionizing fields such as telecommunications, computing, and medical imaging. Quantum computing, which leverages the principles of superposition and entanglement, holds the potential to solve complex problems that are currently intractable for classical computers. On the other hand, the probabilistic nature of quantum mechanics and the challenges of controlling and measuring quantum systems pose significant obstacles for practical applications. In conclusion, quantum mechanics has had a profound impact on our understanding of the universe, challenging classical notions of determinism and causality. The historical development of quantum mechanics was marked by intense debates and differing perspectives among physicists, leading to various interpretations of the theory. Examples such as "Schrodinger's cat" illustrate the peculiarities of quantum phenomena and the role of observation in determining the state of a system. The implications of quantum mechanics have been both beneficial and challenging, leading to technological advancements while posing significant obstacles for practical applications. As research in quantum mechanics continues to advance, it is essential to critically evaluate the benefits and drawbacks of the theory and consider its future implications for science and technology.。
论量子力学与三个代表
论量子力学与三个代表论量子力学与三个代表量子力学的建立与科技创新的评价体系—纪念普朗克创立量子论100周年何柞麻(中国科学院理论物理研究所，北京100080)[摘要]通过量子力学的建立与发展、奠定了原子能、计算机、光纤通讯、激光技术的理论基础，证明了科学技术是第一生产力的论述的科学性。
通过量子力学的发展，论证了同志关于“三个代表”的理论是科技创新评价体系的根本性标准。
[关键词]量子力学;科技创新;评价标准[中图分类号]04-1[文献标识码] A[文章编号]CN 53-1160/C (2001) 01-0003-06The Establishment of Quantum Mechanics and the Evaluation System of Scientific and Technological Innovation— In Commemoration of the 100th Anniversary ofthe Establishment of Planch Quantum TheoryHE Zuo-xiu(Chinese Academy of Science, Beijing, 100080, China)Abstract: The establishment and development of quantum mechanics lay down the theoretical foundation for the development of atomic energy, c完达山uter, fiber-optical communication and laser technology. It also attests to the scientificalness of the theory that science.and technology are the first productive force. The development of quantum mechanics argues that Jiang Zeming's theory on "Three Representativesthe fundamental criterion of the evaluation system of scientific and technological innovation.Key words:quantum mechanics; scientific and technological innovation; evaluation system1900年的12月14日，普朗克宣布创立了量子论。
MyFriend,AlbertEinstein课文翻译
我的朋友阿尔伯特•爱因斯坦班尼旭·霍夫曼爱因斯坦是历史上最伟大的科学家，如果用一个词出神入化地描述他，那就是“率真”。
有个例子很能表现他的率真：一次，爱因斯坦突遇大雨，他脱下帽子将其藏在衣内。
问及为什么这样，他很有逻辑地说，大雨会淋坏帽子，脱下帽子，头发受淋没什么关系。
真是一语切入问题实质。
正是这种人品素质，以及他对美的非凡感受，才是奠定他重大科学发现的秘诀。
第一次见到爱因斯坦，是1935年，在新泽西州普林斯顿那所著名的高级研究院里。
他是受研究院邀请最早的学者之一，薪金任他自己填写。
可令院长失望的是，爱因斯坦填写的薪金太少了，院长不得不恳请先生多填一些。
我非常敬畏爱因斯坦。
一次，我正在研究一个问题，必须向先生请教。
临行前，我一直犹犹豫豫。
当我终于敲响先生的屋门时，听到一声温和的“请进！”-------声调微微上扬，透着欢迎和询问的语气。
我走进办公室，见先生坐在桌前，一边吸烟一边做计算。
他头发有些凌乱，一副不修边幅的样子。
他对我颔首微笑，平易的面容使我立即消除了紧张感。
我开始解释自己的想法。
他让我把公式写在黑板上，以便能看明白每一个发展步骤。
“请你慢慢说，我接受力很慢。
”先生的请求令我愕然，也使我倍感亲切。
这话竟出自爱因斯坦之口，而且说得那么温和！我笑了。
所有的拘束荡然无存。
与爱因斯坦合作让我终身不忘。
1937年我和波兰物理学家奥波德•英费尔德请求与先生一起工作，他愉快地答应了。
当时，他的万有引力设想正待进一步研究和证明。
这以后，工作中的朝夕相处，使我们不仅接近和了解了作为人，作为朋友的爱因斯坦，更了解了作为科学家的爱因斯坦。
爱因斯坦研究之专注，是无与伦比的。
较量难题，他犹如野兽扑食物。
每当我们陷入一个近乎难以超越的困境，爱因斯坦便习惯地站起来，放下烟斗，用他那滑稽的英语说“我想想”（他发不”th”这个音，所以把“think”说成了“ tink”）。
边说边在屋里来回踱步，食指还不停地捻弄他那一头乱发。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
Chapter 33 Early Quantum Theory and Models of the Atom
2) Wien’s 维恩位移定律
Two important theoretical curves on blackbody based on classical ideas were those proposed by W.Wien (in 1896) .
Chapter 33 Early Quantum Theory and Models of the Atom
随即被赫兹的实验所证实。后来又把牛顿、惠更斯和 菲涅耳所建立的光学也纳入了电动力学的范畴，更是 一项辉煌的成就。因此当时许多著名的物理学家都认 为物理学的基本规律都已被发现，就连当时赫赫有名 的权威人物开耳文勋爵在一篇于1900年发表的瞻望二 十世纪物理学发展的文章中也说：“在已经基本建成 的科学大厦中，后辈物理学家只需要做一些零星的修 补工作就行了”，不过他还不愧为一名确有远见卓识 的物理学家，因为他接着又指出：“但是在物理晴朗 天空的远处，还有两朵小小令人不安的乌云”，即运 用当时的物理学理论所无法正确解释的两个实验现象， 一个是热辐射现象中的紫外灾难，另一个是否定绝对 时空观的迈克尔逊--莫雷实验，正是这两朵小小的乌云， 冲破了经典物理学的束缚，打消了当时绝大多数物理 学家的盲目乐观情绪，为后来建立近代物理学的理论 基础
任何物体（气、液、固）在任何温度下，都会有 热辐射，只是在不同的温度下所发出的各种电磁波的 能量按波长（频率）有不同的分布，所以才表现出各 种颜色。低温物体发出的是红外光，炽热物体发出的 是可见光，极高温物体发出的是紫外光。
All objects emit electromagnetic radiation at any temperature. As the temperature increases, the electromagnetic radiation emitted by bodies is most intense at higher and higher frequencies.
瑞利 - 金斯公式
6 5 4 3
* * 实验曲线 * * * * * * T 2000k * 2 * * * 1 * * * * 0 1 2 3 14
瑞利 - 金斯公式
2 π M (T ) kT 2 c
2
紫外灾难
/ 10 Hz
Chapter 33 Early Quantum Theory and Models of the Atom
work function
爱因斯光电方程
逸出功
compton effect
matter wave (de Broglie wave)
康普顿效应
物质波
Wave-Particle Duality
Complementarity
波粒二象性
互补性
Chapter 33 Early Quantum Theory and Models of the Atom
Chapter 33 Early Quantum Theory and Models of the Atom
量子概念是 1900 年普朗克首先提出的，距今已 有一百多年的历史.其间，经过爱因斯坦、玻尔、德 布罗意、玻恩、海森伯、薛定谔、狄拉克等许多物理 大师的创新努力，到 20 世纪 30 年代，就建立了一 套完整的量子力学理论. 微观世界的理论 量子力学
1) 热辐射 实验证明不同温度下物体能发出不同的电 磁波，这种能量按频率的分布Hale Waihona Puke 温度而不同的电磁辐 射叫做热辐射.
A we known that all objects emit radiation whose total intensity is proportional to the fourth power of the Kelvin temperature.
2. Blackbody (黑体) 能完全吸收照射到它上面的各种频率的电磁辐射的 物体称为黑体 .A blackbody is a body that would
absorb all the radiation falling on it.
Chapter 33 Early Quantum Theory and Models of the Atom
The rate at which an object emits energy via electromagnetic radiation depends on the object’s surface area A and the temperature T of that area in Kelvins and is given by
Chapter 33 Early Quantum Theory and Models of the Atom
Chapter 33
Early Quantum Theory and Models of the Atom
1. Planck’s Quantum Hypothesis 2. The Photoelectric Effect 3. Compton Effect 4. Wave Nature of Matter
辐射
普朗克假设
quantized
The photoelectric effect stopping potential
量子化
光电效应 遏止电压
Chapter 33 Early Quantum Theory and Models of the Atom
cutoff frequency
红限频率
Einstein’s Photoelectric Equation
800K
1000K
1200K 1400K Shorter wavelength
例如：加热铁块，温度，铁块颜色由看不出发 光 暗红 橙色 黄白色 蓝白色。
Chapter 33 Early Quantum Theory and Models of the Atom
红外照相机拍摄的人的头部的热图 热的地方显白色，冷的地方显黑色
量子物理引言
到十九世纪末期，物理学各个分支的发展都已日臻 完善，并不断取得新的成就。首先在牛顿力学基础上， 哈密顿和拉格朗日等人建立起来的分析力学，几乎达到 无懈可击的地步，特别是十九世纪中期，海王星的发现 充分表明了牛顿力学是完美无缺的。其次，通过克劳修 斯、玻耳兹曼和吉布斯等人的巨大努力，建立了体系完 整而又严密的热力学和统计力学，并且应用越来越广泛。 由安培、法拉第和麦克斯韦等人对电磁现象进行的深入 而系统的研究，为电动力学奠定了坚实的基础，特别是 由麦克斯韦的电磁场方程组预言了电磁波的存在，
Chapter 33 Early Quantum Theory and Models of the Atom
作出了贡献。事实上还有第三朵小小的乌云，这就是 放射性现象的发现，它有力地表明了原子不是构成物 质的基本单元，原子也是可以分割的。
所有这些实验结果都是经典物理学无法解释的， 它们使经典物理处于十分困难境地，为摆脱这种困境， 有一些思想敏锐而又不受旧观念束缚的物理学家纷纷 重新思考研究，在二十世纪初期，建立起了近代物理 的两大支柱------量子论和相对论，并在这个基础上又 建立起以研究原子的结构、性质及其运动规律为目的 的原子物理学，后来又进一步发展，相继建立起原子 核物理学和基本粒子物理学，这些内容统称为量子物 理学。
实验表明 辐射能力越强的物体，其吸收能力也越强.
A good absorber is also a good emitter.
Chapter 33 Early Quantum Theory and Models of the Atom
Any heated solid or liquid, and even by dense gases, can continuously radiate electromagnetic wave which contains a continuous range of wavelength.
对宇宙中其他发光星体的表面温度也可用这种方
法进行推测.
Examples 33-1 and 33-2 on page 764
Chapter 33 Early Quantum Theory and Models of the Atom
3) Rayleigh-Jeans theory 瑞利—金斯公式
M (T )(109 W/(m 2 Hz ))
Chapter 33 Early Quantum Theory and Models of the Atom
第五次索尔维会议与会者合影(1927年)
N.玻尔、M.玻恩、 W.L.布拉格、L.V.德布罗意、A.H.康 普顿、M.居里、P.A.M 狄喇克、A.爱因斯坦、W.K.海森 堡、郞之万、W.泡利、普朗克、薛定谔 等
M (T ) M (T )d T
0 4
This is called the Stefan-Boltzman equation, and is a universal (Stefan-Boltzman) constant
斯特藩—玻尔兹曼常量
5.670108 W m2 K 4
面积上所辐射出的各
M (T ) M (T )d
0
8 6 4 2 0
钨丝 （5800K）
M (T ) M (T )d
0
/ 1014 Hz
2 4 6 8 10 12
Chapter 33 Early Quantum Theory and Models of the Atom
维恩位移定律
mT b
峰值波长 常量 b 2.898 10 m K