physicdal optics 04 Polarization of light
2004年诺贝尔物理学奖
2004年诺贝尔物理学奖2004年物理学奖，由三位美国的物理学家分享，他们是戴维·格罗斯（David J.Gross）、休·普利策（Hugh David Politzer）和弗兰克·维尔泽克（Frank Wilczek。
他们提出了量子场中夸克“渐进自由”的理论。
戴维·乔纳森·格罗斯（David Jonathan Gross，1941—），出生于美国华盛顿。
1966年获得美国加州大学伯克利分校博士学位。
1985年当选为美国科学与艺术学院院士，1986年当选为美国科学院院士，2011年当选为中国科学院外籍院士。
格罗斯在理论物理，尤其是规范场理论、粒子物理和超弦理论等方面做出了一系列开创性的研究成果。
他是量子色动力学的主要奠基人之一。
量子色动力学作为描述自然界四种基本作用力之一的“强相互作用力”的基本理论，成为研究强子性质和原子核物理的基础。
休·戴维·普利策（Hugh David Politzer，1949—），出生于美国纽约。
1974年获得哈佛大学的物理学博士学位，后在加利福尼亚理工学院物理系任教授，同时也是该校粒子物理研究领域的学术带头人之一。
加州理工学院坐落于帕萨迪纳美丽的圣盖伯利山脚下，是美国声名显赫的名牌私立大学之一。
弗兰克·维尔泽克（Frank Wilczek，1951—），出生在纽约州的米里奥拉，他的祖先来自波兰和意大利。
他在昆斯区上中小学。
在芝加哥大学物理系本科毕业后，前往普林斯顿大学继续深造，1972年获得数学硕士学位，1974年获得物1理学博士学位。
毕业后在普林斯顿开始执教生涯。
1988年他前往美国西海岸的加利福尼亚大学圣巴巴拉分校担任教授。
2000年秋天，他重回东海岸，担任麻省理工学院的物理系教授。
他被誉为美国最杰出的理论物理科学家之一。
维尔泽克曾是戴维·格罗斯的学生。
近代物理学理论认为，夸克等是比质子和中子等亚原子粒子更基本的物质组成单位，夸克等组成了质子和中子，中子和质子又形成原子核，最终产生原子以及今天的宇宙万物。
磁学 径向克尔 英文 kerr effect
IntroductionThe Kerr effect, also known as the magneto-optic Kerr effect (MOKE), is a phenomenon that manifests the interaction between light and magnetic fields in a material. It is named after its discoverer, John Kerr, who observed this effect in 1877. The radial Kerr effect, specifically, refers to the variation in polarization state of light upon reflection from a magnetized surface, where the change occurs radially with respect to the magnetization direction. This unique aspect of the Kerr effect has significant implications in various scientific disciplines, including condensed matter physics, materials science, and optoelectronics. This paper presents a comprehensive, multifaceted analysis of the radial Kerr effect, delving into its underlying principles, experimental techniques, applications, and ongoing research directions.I. Theoretical Foundations of the Radial Kerr EffectA. Basic PrinciplesThe radial Kerr effect arises due to the anisotropic nature of the refractive index of a ferromagnetic or ferrimagnetic material when subjected to an external magnetic field. When linearly polarized light impinges on such a magnetized surface, the reflected beam experiences a change in its polarization state, which is characterized by a rotation of the plane of polarization and/or a change in ellipticity. This alteration is radially dependent on the orientation of the magnetization vector relative to the incident light's plane of incidence. The radial Kerr effect is fundamentally governed by the Faraday-Kerr law, which describes the relationship between the change in polarization angle (ΔθK) and the applied magnetic field (H):ΔθK = nHKVwhere n is the sample's refractive index, H is the magnetic field strength, K is the Kerr constant, and V is the Verdet constant, which depends on the wavelength of the incident light and the magnetic properties of the material.B. Microscopic MechanismsAt the microscopic level, the radial Kerr effect can be attributed to twoprimary mechanisms: the spin-orbit interaction and the exchange interaction. The spin-orbit interaction arises from the coupling between the electron's spin and its orbital motion in the presence of an electric field gradient, leading to a magnetic-field-dependent modification of the electron density distribution and, consequently, the refractive index. The exchange interaction, on the other hand, influences the Kerr effect through its role in determining the magnetic structure and the alignment of magnetic moments within the material.C. Material DependenceThe magnitude and sign of the radial Kerr effect are highly dependent on the magnetic and optical properties of the material under investigation. Ferromagnetic and ferrimagnetic materials generally exhibit larger Kerr rotations due to their strong net magnetization. Additionally, the effect is sensitive to factors such as crystal structure, chemical composition, and doping levels, making it a valuable tool for studying the magnetic and electronic structure of complex materials.II. Experimental Techniques for Measuring the Radial Kerr EffectA. MOKE SetupA typical MOKE setup consists of a light source, polarizers, a magnetized sample, and a detector. In the case of radial Kerr measurements, the sample is usually magnetized along a radial direction, and the incident light is either p-polarized (electric field parallel to the plane of incidence) or s-polarized (electric field perpendicular to the plane of incidence). By monitoring the change in the polarization state of the reflected light as a function of the applied magnetic field, the radial Kerr effect can be quantified.B. Advanced MOKE TechniquesSeveral advanced MOKE techniques have been developed to enhance the sensitivity and specificity of radial Kerr effect measurements. These include polar MOKE, longitudinal MOKE, and polarizing neutron reflectometry, each tailored to probe different aspects of the magnetic structure and dynamics. Moreover, time-resolved MOKE setups enable the study of ultrafast magneticphenomena, such as spin dynamics and all-optical switching, by employing pulsed laser sources and high-speed detection systems.III. Applications of the Radial Kerr EffectA. Magnetic Domain Imaging and CharacterizationThe radial Kerr effect plays a crucial role in visualizing and analyzing magnetic domains in ferromagnetic and ferrimagnetic materials. By raster-scanning a focused laser beam over the sample surface while monitoring the Kerr signal, high-resolution maps of domain patterns, domain wall structures, and magnetic domain evolution can be obtained. This information is vital for understanding the fundamental mechanisms governing magnetic behavior and optimizing the performance of magnetic devices.B. Magnetometry and SensingDue to its sensitivity to both the magnitude and direction of the magnetic field, the radial Kerr effect finds applications in magnetometry and sensing technologies. MOKE-based sensors offer high spatial resolution, non-destructive testing capabilities, and compatibility with various sample geometries, making them suitable for applications ranging from magnetic storage media characterization to biomedical imaging.C. Spintronics and MagnonicsThe radial Kerr effect is instrumental in investigating spintronic and magnonic phenomena, where the manipulation and control of spin degrees of freedom in solids are exploited for novel device concepts. For instance, it can be used to study spin-wave propagation, spin-transfer torque effects, and all-optical magnetic switching, which are key elements in the development of spintronic memory, logic devices, and magnonic circuits.IV. Current Research Directions and Future PerspectivesA. Advanced Materials and NanostructuresOngoing research in the field focuses on exploring the radial Kerr effect in novel magnetic materials, such as multiferroics, topological magnets, and magnetic thin films and nanostructures. These studies aim to uncover newmagnetooptical phenomena, understand the interplay between magnetic, electric, and structural order parameters, and develop materials with tailored Kerr responses for next-generation optoelectronic and spintronic applications.B. Ultrafast Magnetism and Spin DynamicsThe advent of femtosecond laser technology has enabled researchers to investigate the radial Kerr effect on ultrafast timescales, revealing fascinating insights into the fundamental processes governing magnetic relaxation, spin precession, and all-optical manipulation of magnetic order. Future work in this area promises to deepen our understanding of ultrafast magnetism and pave the way for the development of ultrafast magnetic switches and memories.C. Quantum Information ProcessingRecent studies have demonstrated the potential of the radial Kerr effect in quantum information processing applications. For example, the manipulation of single spins in solid-state systems using the radial Kerr effect could lead to the realization of scalable, robust quantum bits (qubits) and quantum communication protocols. Further exploration in this direction may open up new avenues for quantum computing and cryptography.ConclusionThe radial Kerr effect, a manifestation of the intricate interplay between light and magnetism, offers a powerful and versatile platform for probing the magnetic properties and dynamics of materials. Its profound impact on various scientific disciplines, coupled with ongoing advancements in experimental techniques and materials engineering, underscores the continued importance of this phenomenon in shaping our understanding of magnetism and driving technological innovations in optoelectronics, spintronics, and quantum information processing. As research in these fields progresses, the radial Kerr effect will undoubtedly continue to serve as a cornerstone for unraveling the mysteries of magnetic materials and harnessing their potential for transformative technologies.。
大学物理课件 光学第三十一章衍射
The condition of two objects are barely resolved by this criterion of an angle separation R (最小分辨角 ): 1.22l R arcsin d d Increasing l For a small angle, l R 1.22 (Rayleigh’s criterion) d Resolving power lf RP f 1.22 d R 1 d Resolvability(分辨本领): R 1.22l
Difference of interference & diffraction? No diffraction:
I I0
Lens
θ
3l l l l 0 2d d 2d 2d
l d
3l 2d
λ
a d
θ
θ
I
设双缝缝宽均为a，在 夫琅禾费衍射下，每缝 衍射图样位置相重叠
f
Considering the diffraction of light.
1. Diffraction (衍射) by a single slit
screen shadow screen
When the slit is wide, light travels in straight lines. When the slit gets narrow, light produces a diffraction pattern on the screen.
is called diffraction of light (P703).
Chapter 19 Polarization
Discussion (1)反射光和折射光互相垂直 . (2) i0 是某一个确定的值，而不是某个“界限”只有 当 i = i0，反射光才是完全偏振光。 (3) 无论入射角是多少，折射光总是 “ ·” 的部分偏 振光，而当i i0，反射光是 “· ” 的部分偏振光 (4)此情形对 n 2
——消光
Note:
各偏振片只允许和自己的偏振 化方向相同的偏振光透过。
Example P722 31-9
Unpolarized light passes through two polaroids; the axis of one is vertical and that of the other is at 60o to the vertical. What is the orientation and intensity of the transmitted light?
自然光I0
线偏振光I
1 2
线偏振光I'
I=
ቤተ መጻሕፍቲ ባይዱ
I0
I = ?
2. Malus law (马吕斯定律)(1809):
I0
P
E0 I
P E=E0cos
I E
I I 0 cos
2
2
E
2 0
co s
2
马吕斯定律（1809）
2 ，I 0
0， I I m ax I 0 ;
n1
或
n1 n 2
都成立
对于一般的光学玻璃 , 反射光的强 度约占入射光强度的7.5% , 大部分光将透过 玻璃. 利用玻璃片堆产生线偏振光
i0
物理学专业英语
华中师范大学物理学院物理学专业英语仅供内部学习参考！2014一、课程的任务和教学目的通过学习《物理学专业英语》，学生将掌握物理学领域使用频率较高的专业词汇和表达方法，进而具备基本的阅读理解物理学专业文献的能力。
通过分析《物理学专业英语》课程教材中的范文，学生还将从英语角度理解物理学中个学科的研究内容和主要思想，提高学生的专业英语能力和了解物理学研究前沿的能力。
培养专业英语阅读能力，了解科技英语的特点，提高专业外语的阅读质量和阅读速度；掌握一定量的本专业英文词汇，基本达到能够独立完成一般性本专业外文资料的阅读；达到一定的笔译水平。
要求译文通顺、准确和专业化。
要求译文通顺、准确和专业化。
二、课程内容课程内容包括以下章节：物理学、经典力学、热力学、电磁学、光学、原子物理、统计力学、量子力学和狭义相对论三、基本要求1.充分利用课内时间保证充足的阅读量（约1200~1500词/学时），要求正确理解原文。
2.泛读适量课外相关英文读物，要求基本理解原文主要内容。
3.掌握基本专业词汇（不少于200词）。
4.应具有流利阅读、翻译及赏析专业英语文献，并能简单地进行写作的能力。
四、参考书目录1 Physics 物理学 (1)Introduction to physics (1)Classical and modern physics (2)Research fields (4)V ocabulary (7)2 Classical mechanics 经典力学 (10)Introduction (10)Description of classical mechanics (10)Momentum and collisions (14)Angular momentum (15)V ocabulary (16)3 Thermodynamics 热力学 (18)Introduction (18)Laws of thermodynamics (21)System models (22)Thermodynamic processes (27)Scope of thermodynamics (29)V ocabulary (30)4 Electromagnetism 电磁学 (33)Introduction (33)Electrostatics (33)Magnetostatics (35)Electromagnetic induction (40)V ocabulary (43)5 Optics 光学 (45)Introduction (45)Geometrical optics (45)Physical optics (47)Polarization (50)V ocabulary (51)6 Atomic physics 原子物理 (52)Introduction (52)Electronic configuration (52)Excitation and ionization (56)V ocabulary (59)7 Statistical mechanics 统计力学 (60)Overview (60)Fundamentals (60)Statistical ensembles (63)V ocabulary (65)8 Quantum mechanics 量子力学 (67)Introduction (67)Mathematical formulations (68)Quantization (71)Wave-particle duality (72)Quantum entanglement (75)V ocabulary (77)9 Special relativity 狭义相对论 (79)Introduction (79)Relativity of simultaneity (80)Lorentz transformations (80)Time dilation and length contraction (81)Mass-energy equivalence (82)Relativistic energy-momentum relation (86)V ocabulary (89)正文标记说明：蓝色Arial字体（例如energy）：已知的专业词汇蓝色Arial字体加下划线（例如electromagnetism）：新学的专业词汇黑色Times New Roman字体加下划线（例如postulate）：新学的普通词汇1 Physics 物理学1 Physics 物理学Introduction to physicsPhysics is a part of natural philosophy and a natural science that involves the study of matter and its motion through space and time, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic disciplines, perhaps the oldest through its inclusion of astronomy. Over the last two millennia, physics was a part of natural philosophy along with chemistry, certain branches of mathematics, and biology, but during the Scientific Revolution in the 17th century, the natural sciences emerged as unique research programs in their own right. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry,and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms of other sciences, while opening new avenues of research in areas such as mathematics and philosophy.Physics also makes significant contributions through advances in new technologies that arise from theoretical breakthroughs. For example, advances in the understanding of electromagnetism or nuclear physics led directly to the development of new products which have dramatically transformed modern-day society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus.Core theoriesThough physics deals with a wide variety of systems, certain theories are used by all physicists. Each of these theories were experimentally tested numerous times and found correct as an approximation of nature (within a certain domain of validity).For instance, the theory of classical mechanics accurately describes the motion of objects, provided they are much larger than atoms and moving at much less than the speed of light. These theories continue to be areas of active research, and a remarkable aspect of classical mechanics known as chaos was discovered in the 20th century, three centuries after the original formulation of classical mechanics by Isaac Newton (1642–1727) 【艾萨克·牛顿】.University PhysicsThese central theories are important tools for research into more specialized topics, and any physicist, regardless of his or her specialization, is expected to be literate in them. These include classical mechanics, quantum mechanics, thermodynamics and statistical mechanics, electromagnetism, and special relativity.Classical and modern physicsClassical mechanicsClassical physics includes the traditional branches and topics that were recognized and well-developed before the beginning of the 20th century—classical mechanics, acoustics, optics, thermodynamics, and electromagnetism.Classical mechanics is concerned with bodies acted on by forces and bodies in motion and may be divided into statics (study of the forces on a body or bodies at rest), kinematics (study of motion without regard to its causes), and dynamics (study of motion and the forces that affect it); mechanics may also be divided into solid mechanics and fluid mechanics (known together as continuum mechanics), the latter including such branches as hydrostatics, hydrodynamics, aerodynamics, and pneumatics.Acoustics is the study of how sound is produced, controlled, transmitted and received. Important modern branches of acoustics include ultrasonics, the study of sound waves of very high frequency beyond the range of human hearing; bioacoustics the physics of animal calls and hearing, and electroacoustics, the manipulation of audible sound waves using electronics.Optics, the study of light, is concerned not only with visible light but also with infrared and ultraviolet radiation, which exhibit all of the phenomena of visible light except visibility, e.g., reflection, refraction, interference, diffraction, dispersion, and polarization of light.Heat is a form of energy, the internal energy possessed by the particles of which a substance is composed; thermodynamics deals with the relationships between heat and other forms of energy.Electricity and magnetism have been studied as a single branch of physics since the intimate connection between them was discovered in the early 19th century; an electric current gives rise to a magnetic field and a changing magnetic field induces an electric current. Electrostatics deals with electric charges at rest, electrodynamics with moving charges, and magnetostatics with magnetic poles at rest.Modern PhysicsClassical physics is generally concerned with matter and energy on the normal scale of1 Physics 物理学observation, while much of modern physics is concerned with the behavior of matter and energy under extreme conditions or on the very large or very small scale.For example, atomic and nuclear physics studies matter on the smallest scale at which chemical elements can be identified.The physics of elementary particles is on an even smaller scale, as it is concerned with the most basic units of matter; this branch of physics is also known as high-energy physics because of the extremely high energies necessary to produce many types of particles in large particle accelerators. On this scale, ordinary, commonsense notions of space, time, matter, and energy are no longer valid.The two chief theories of modern physics present a different picture of the concepts of space, time, and matter from that presented by classical physics.Quantum theory is concerned with the discrete, rather than continuous, nature of many phenomena at the atomic and subatomic level, and with the complementary aspects of particles and waves in the description of such phenomena.The theory of relativity is concerned with the description of phenomena that take place in a frame of reference that is in motion with respect to an observer; the special theory of relativity is concerned with relative uniform motion in a straight line and the general theory of relativity with accelerated motion and its connection with gravitation.Both quantum theory and the theory of relativity find applications in all areas of modern physics.Difference between classical and modern physicsWhile physics aims to discover universal laws, its theories lie in explicit domains of applicability. Loosely speaking, the laws of classical physics accurately describe systems whose important length scales are greater than the atomic scale and whose motions are much slower than the speed of light. Outside of this domain, observations do not match their predictions.Albert Einstein【阿尔伯特·爱因斯坦】contributed the framework of special relativity, which replaced notions of absolute time and space with space-time and allowed an accurate description of systems whose components have speeds approaching the speed of light.Max Planck【普朗克】, Erwin Schrödinger【薛定谔】, and others introduced quantum mechanics, a probabilistic notion of particles and interactions that allowed an accurate description of atomic and subatomic scales.Later, quantum field theory unified quantum mechanics and special relativity.General relativity allowed for a dynamical, curved space-time, with which highly massiveUniversity Physicssystems and the large-scale structure of the universe can be well-described. General relativity has not yet been unified with the other fundamental descriptions; several candidate theories of quantum gravity are being developed.Research fieldsContemporary research in physics can be broadly divided into condensed matter physics; atomic, molecular, and optical physics; particle physics; astrophysics; geophysics and biophysics. Some physics departments also support research in Physics education.Since the 20th century, the individual fields of physics have become increasingly specialized, and today most physicists work in a single field for their entire careers. "Universalists" such as Albert Einstein (1879–1955) and Lev Landau (1908–1968)【列夫·朗道】, who worked in multiple fields of physics, are now very rare.Condensed matter physicsCondensed matter physics is the field of physics that deals with the macroscopic physical properties of matter. In particular, it is concerned with the "condensed" phases that appear whenever the number of particles in a system is extremely large and the interactions between them are strong.The most familiar examples of condensed phases are solids and liquids, which arise from the bonding by way of the electromagnetic force between atoms. More exotic condensed phases include the super-fluid and the Bose–Einstein condensate found in certain atomic systems at very low temperature, the superconducting phase exhibited by conduction electrons in certain materials,and the ferromagnetic and antiferromagnetic phases of spins on atomic lattices.Condensed matter physics is by far the largest field of contemporary physics.Historically, condensed matter physics grew out of solid-state physics, which is now considered one of its main subfields. The term condensed matter physics was apparently coined by Philip Anderson when he renamed his research group—previously solid-state theory—in 1967. In 1978, the Division of Solid State Physics of the American Physical Society was renamed as the Division of Condensed Matter Physics.Condensed matter physics has a large overlap with chemistry, materials science, nanotechnology and engineering.Atomic, molecular and optical physicsAtomic, molecular, and optical physics (AMO) is the study of matter–matter and light–matter interactions on the scale of single atoms and molecules.1 Physics 物理学The three areas are grouped together because of their interrelationships, the similarity of methods used, and the commonality of the energy scales that are relevant. All three areas include both classical, semi-classical and quantum treatments; they can treat their subject from a microscopic view (in contrast to a macroscopic view).Atomic physics studies the electron shells of atoms. Current research focuses on activities in quantum control, cooling and trapping of atoms and ions, low-temperature collision dynamics and the effects of electron correlation on structure and dynamics. Atomic physics is influenced by the nucleus (see, e.g., hyperfine splitting), but intra-nuclear phenomena such as fission and fusion are considered part of high-energy physics.Molecular physics focuses on multi-atomic structures and their internal and external interactions with matter and light.Optical physics is distinct from optics in that it tends to focus not on the control of classical light fields by macroscopic objects, but on the fundamental properties of optical fields and their interactions with matter in the microscopic realm.High-energy physics (particle physics) and nuclear physicsParticle physics is the study of the elementary constituents of matter and energy, and the interactions between them.In addition, particle physicists design and develop the high energy accelerators,detectors, and computer programs necessary for this research. The field is also called "high-energy physics" because many elementary particles do not occur naturally, but are created only during high-energy collisions of other particles.Currently, the interactions of elementary particles and fields are described by the Standard Model.●The model accounts for the 12 known particles of matter (quarks and leptons) thatinteract via the strong, weak, and electromagnetic fundamental forces.●Dynamics are described in terms of matter particles exchanging gauge bosons (gluons,W and Z bosons, and photons, respectively).●The Standard Model also predicts a particle known as the Higgs boson. In July 2012CERN, the European laboratory for particle physics, announced the detection of a particle consistent with the Higgs boson.Nuclear Physics is the field of physics that studies the constituents and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those in nuclear medicine and magnetic resonance imaging, ion implantation in materials engineering, and radiocarbon dating in geology and archaeology.University PhysicsAstrophysics and Physical CosmologyAstrophysics and astronomy are the application of the theories and methods of physics to the study of stellar structure, stellar evolution, the origin of the solar system, and related problems of cosmology. Because astrophysics is a broad subject, astrophysicists typically apply many disciplines of physics, including mechanics, electromagnetism, statistical mechanics, thermodynamics, quantum mechanics, relativity, nuclear and particle physics, and atomic and molecular physics.The discovery by Karl Jansky in 1931 that radio signals were emitted by celestial bodies initiated the science of radio astronomy. Most recently, the frontiers of astronomy have been expanded by space exploration. Perturbations and interference from the earth's atmosphere make space-based observations necessary for infrared, ultraviolet, gamma-ray, and X-ray astronomy.Physical cosmology is the study of the formation and evolution of the universe on its largest scales. Albert Einstein's theory of relativity plays a central role in all modern cosmological theories. In the early 20th century, Hubble's discovery that the universe was expanding, as shown by the Hubble diagram, prompted rival explanations known as the steady state universe and the Big Bang.The Big Bang was confirmed by the success of Big Bang nucleo-synthesis and the discovery of the cosmic microwave background in 1964. The Big Bang model rests on two theoretical pillars: Albert Einstein's general relativity and the cosmological principle (On a sufficiently large scale, the properties of the Universe are the same for all observers). Cosmologists have recently established the ΛCDM model (the standard model of Big Bang cosmology) of the evolution of the universe, which includes cosmic inflation, dark energy and dark matter.Current research frontiersIn condensed matter physics, an important unsolved theoretical problem is that of high-temperature superconductivity. Many condensed matter experiments are aiming to fabricate workable spintronics and quantum computers.In particle physics, the first pieces of experimental evidence for physics beyond the Standard Model have begun to appear. Foremost among these are indications that neutrinos have non-zero mass. These experimental results appear to have solved the long-standing solar neutrino problem, and the physics of massive neutrinos remains an area of active theoretical and experimental research. Particle accelerators have begun probing energy scales in the TeV range, in which experimentalists are hoping to find evidence for the super-symmetric particles, after discovery of the Higgs boson.Theoretical attempts to unify quantum mechanics and general relativity into a single theory1 Physics 物理学of quantum gravity, a program ongoing for over half a century, have not yet been decisively resolved. The current leading candidates are M-theory, superstring theory and loop quantum gravity.Many astronomical and cosmological phenomena have yet to be satisfactorily explained, including the existence of ultra-high energy cosmic rays, the baryon asymmetry, the acceleration of the universe and the anomalous rotation rates of galaxies.Although much progress has been made in high-energy, quantum, and astronomical physics, many everyday phenomena involving complexity, chaos, or turbulence are still poorly understood. Complex problems that seem like they could be solved by a clever application of dynamics and mechanics remain unsolved; examples include the formation of sand-piles, nodes in trickling water, the shape of water droplets, mechanisms of surface tension catastrophes, and self-sorting in shaken heterogeneous collections.These complex phenomena have received growing attention since the 1970s for several reasons, including the availability of modern mathematical methods and computers, which enabled complex systems to be modeled in new ways. Complex physics has become part of increasingly interdisciplinary research, as exemplified by the study of turbulence in aerodynamics and the observation of pattern formation in biological systems.Vocabulary★natural science 自然科学academic disciplines 学科astronomy 天文学in their own right 凭他们本身的实力intersects相交，交叉interdisciplinary交叉学科的，跨学科的★quantum 量子的theoretical breakthroughs 理论突破★electromagnetism 电磁学dramatically显著地★thermodynamics热力学★calculus微积分validity★classical mechanics 经典力学chaos 混沌literate 学者★quantum mechanics量子力学★thermodynamics and statistical mechanics热力学与统计物理★special relativity狭义相对论is concerned with 关注，讨论，考虑acoustics 声学★optics 光学statics静力学at rest 静息kinematics运动学★dynamics动力学ultrasonics超声学manipulation 操作，处理，使用University Physicsinfrared红外ultraviolet紫外radiation辐射reflection 反射refraction 折射★interference 干涉★diffraction 衍射dispersion散射★polarization 极化，偏振internal energy 内能Electricity电性Magnetism 磁性intimate 亲密的induces 诱导，感应scale尺度★elementary particles基本粒子★high-energy physics 高能物理particle accelerators 粒子加速器valid 有效的，正当的★discrete离散的continuous 连续的complementary 互补的★frame of reference 参照系★the special theory of relativity 狭义相对论★general theory of relativity 广义相对论gravitation 重力，万有引力explicit 详细的，清楚的★quantum field theory 量子场论★condensed matter physics凝聚态物理astrophysics天体物理geophysics地球物理Universalist博学多才者★Macroscopic宏观Exotic奇异的★Superconducting 超导Ferromagnetic铁磁质Antiferromagnetic 反铁磁质★Spin自旋Lattice 晶格，点阵，网格★Society社会，学会★microscopic微观的hyperfine splitting超精细分裂fission分裂，裂变fusion熔合，聚变constituents成分，组分accelerators加速器detectors 检测器★quarks夸克lepton 轻子gauge bosons规范玻色子gluons胶子★Higgs boson希格斯玻色子CERN欧洲核子研究中心★Magnetic Resonance Imaging磁共振成像，核磁共振ion implantation 离子注入radiocarbon dating放射性碳年代测定法geology地质学archaeology考古学stellar 恒星cosmology宇宙论celestial bodies 天体Hubble diagram 哈勃图Rival竞争的★Big Bang大爆炸nucleo-synthesis核聚合，核合成pillar支柱cosmological principle宇宙学原理ΛCDM modelΛ-冷暗物质模型cosmic inflation宇宙膨胀1 Physics 物理学fabricate制造，建造spintronics自旋电子元件，自旋电子学★neutrinos 中微子superstring 超弦baryon重子turbulence湍流，扰动，骚动catastrophes突变，灾变，灾难heterogeneous collections异质性集合pattern formation模式形成University Physics2 Classical mechanics 经典力学IntroductionIn physics, classical mechanics is one of the two major sub-fields of mechanics, which is concerned with the set of physical laws describing the motion of bodies under the action of a system of forces. The study of the motion of bodies is an ancient one, making classical mechanics one of the oldest and largest subjects in science, engineering and technology.Classical mechanics describes the motion of macroscopic objects, from projectiles to parts of machinery, as well as astronomical objects, such as spacecraft, planets, stars, and galaxies. Besides this, many specializations within the subject deal with gases, liquids, solids, and other specific sub-topics.Classical mechanics provides extremely accurate results as long as the domain of study is restricted to large objects and the speeds involved do not approach the speed of light. When the objects being dealt with become sufficiently small, it becomes necessary to introduce the other major sub-field of mechanics, quantum mechanics, which reconciles the macroscopic laws of physics with the atomic nature of matter and handles the wave–particle duality of atoms and molecules. In the case of high velocity objects approaching the speed of light, classical mechanics is enhanced by special relativity. General relativity unifies special relativity with Newton's law of universal gravitation, allowing physicists to handle gravitation at a deeper level.The initial stage in the development of classical mechanics is often referred to as Newtonian mechanics, and is associated with the physical concepts employed by and the mathematical methods invented by Newton himself, in parallel with Leibniz【莱布尼兹】, and others.Later, more abstract and general methods were developed, leading to reformulations of classical mechanics known as Lagrangian mechanics and Hamiltonian mechanics. These advances were largely made in the 18th and 19th centuries, and they extend substantially beyond Newton's work, particularly through their use of analytical mechanics. Ultimately, the mathematics developed for these were central to the creation of quantum mechanics.Description of classical mechanicsThe following introduces the basic concepts of classical mechanics. For simplicity, it often2 Classical mechanics 经典力学models real-world objects as point particles, objects with negligible size. The motion of a point particle is characterized by a small number of parameters: its position, mass, and the forces applied to it.In reality, the kind of objects that classical mechanics can describe always have a non-zero size. (The physics of very small particles, such as the electron, is more accurately described by quantum mechanics). Objects with non-zero size have more complicated behavior than hypothetical point particles, because of the additional degrees of freedom—for example, a baseball can spin while it is moving. However, the results for point particles can be used to study such objects by treating them as composite objects, made up of a large number of interacting point particles. The center of mass of a composite object behaves like a point particle.Classical mechanics uses common-sense notions of how matter and forces exist and interact. It assumes that matter and energy have definite, knowable attributes such as where an object is in space and its speed. It also assumes that objects may be directly influenced only by their immediate surroundings, known as the principle of locality.In quantum mechanics objects may have unknowable position or velocity, or instantaneously interact with other objects at a distance.Position and its derivativesThe position of a point particle is defined with respect to an arbitrary fixed reference point, O, in space, usually accompanied by a coordinate system, with the reference point located at the origin of the coordinate system. It is defined as the vector r from O to the particle.In general, the point particle need not be stationary relative to O, so r is a function of t, the time elapsed since an arbitrary initial time.In pre-Einstein relativity (known as Galilean relativity), time is considered an absolute, i.e., the time interval between any given pair of events is the same for all observers. In addition to relying on absolute time, classical mechanics assumes Euclidean geometry for the structure of space.Velocity and speedThe velocity, or the rate of change of position with time, is defined as the derivative of the position with respect to time. In classical mechanics, velocities are directly additive and subtractive as vector quantities; they must be dealt with using vector analysis.When both objects are moving in the same direction, the difference can be given in terms of speed only by ignoring direction.University PhysicsAccelerationThe acceleration , or rate of change of velocity, is the derivative of the velocity with respect to time (the second derivative of the position with respect to time).Acceleration can arise from a change with time of the magnitude of the velocity or of the direction of the velocity or both . If only the magnitude v of the velocity decreases, this is sometimes referred to as deceleration , but generally any change in the velocity with time, including deceleration, is simply referred to as acceleration.Inertial frames of referenceWhile the position and velocity and acceleration of a particle can be referred to any observer in any state of motion, classical mechanics assumes the existence of a special family of reference frames in terms of which the mechanical laws of nature take a comparatively simple form. These special reference frames are called inertial frames .An inertial frame is such that when an object without any force interactions (an idealized situation) is viewed from it, it appears either to be at rest or in a state of uniform motion in a straight line. This is the fundamental definition of an inertial frame. They are characterized by the requirement that all forces entering the observer's physical laws originate in identifiable sources (charges, gravitational bodies, and so forth).A non-inertial reference frame is one accelerating with respect to an inertial one, and in such a non-inertial frame a particle is subject to acceleration by fictitious forces that enter the equations of motion solely as a result of its accelerated motion, and do not originate in identifiable sources. These fictitious forces are in addition to the real forces recognized in an inertial frame.A key concept of inertial frames is the method for identifying them. For practical purposes, reference frames that are un-accelerated with respect to the distant stars are regarded as good approximations to inertial frames.Forces; Newton's second lawNewton was the first to mathematically express the relationship between force and momentum . Some physicists interpret Newton's second law of motion as a definition of force and mass, while others consider it a fundamental postulate, a law of nature. Either interpretation has the same mathematical consequences, historically known as "Newton's Second Law":a m t v m t p F ===d )(d d dThe quantity m v is called the (canonical ) momentum . The net force on a particle is thus equal to rate of change of momentum of the particle with time.So long as the force acting on a particle is known, Newton's second law is sufficient to。
保罗·狄拉克——英国著名理论物理学家
保罗·狄拉克——英国著名理论物理学家狄拉克介绍中文名：保罗·狄拉克外文名：Paul Dirac国籍：英国出生地：英格兰西南部布里斯托出生日期：1902年8月8日逝世日期：1984年10月20日职业：理论物理学家毕业院校：布里斯托大学(学士)，剑桥大学圣约翰学院(硕士，博士)主要成就：1933年，和埃尔温·薛定谔共同获得诺贝尔物理学奖。
量子力学的奠基者之一代表作品：《量子力学原理》保罗·狄拉克，OM，FRS(Paul Adrien Maurice Dirac，1902年8月8日-1984年10月20日)，英国理论物理学家，量子力学的奠基者之一，并对量子电动力学早期的发展作出重要贡献。
曾经主持剑桥大学的卢卡斯数学教授席位，并在佛罗里达州立大学度过他人生的最后十四个年头。
他给出的狄拉克方程可以描述费米子的物理行为，并且预测了反物质的存在。
1933年，因为“发现了在原子理论里很有用的新形式”(即量子力学的基本方程——薛定谔方程和狄拉克方程)，狄拉克和埃尔温·薛定谔共同获得了诺贝尔物理学奖。
家庭背景保罗·狄拉克(P.A.M.Dirac)的父亲查尔斯·狄拉克于1866年出生在瑞士瓦莱州(一个讲法语的州)的蒙泰，直到1919年才成为英国公民。
20岁时，查尔斯背叛家庭，远走他乡至日内瓦大学学习。
之后，大约在1890年来到英格兰，定居在布里斯托尔，以教法语为生。
1896年，他在布里斯托尔商业职业技术学校谋得一席教职，并在布里斯托尔邂逅了弗洛伦斯·霍尔滕(她是个船长的女儿，比查尔斯小12岁)，1899年和她完婚。
结婚一年后，他们的第一个孩子雷金纳德·狄拉克出生，又过了两年，1902年8月8日，保罗·狄拉克降生，他们家那时住在蒙克(Monk)大街。
又过了四年，狄拉克家庭的第三个孩子比阿特丽斯·玛格丽特·狄拉克也诞生了。
2007年诺贝尔物理学奖
2007年诺贝尔物理学奖2007年物理学奖，由两位物理学家分享，他们是法国的艾尔伯·费尔（Albert Fert）和德国的皮特·克鲁伯格（Peter Grünberg）。
他们于1988年，各自独立地发现了巨磁电阻效应，极大地提高了电脑硬盘的数据存储量。
艾尔伯·费尔（Albert Fert，1938—），出生于法国的卡尔卡松。
1962年，费尔在巴黎高等师范学院获得数学和物理硕士学位。
1970年，费尔从巴黎第十一大学获得物理学博士学位，并留校任教。
费尔从1970年到1995年一直在巴黎第十一大学固体物理实验室工作，后任研究小组组长。
1995年至今则担任国家科学研究中心-Thales集团联合物理小组科学主管。
1988年，费尔发现巨磁电阻效应，同时他对自旋电子学作出过许多贡献。
皮特·克鲁伯格（Peter Grünberg，1939—2018），出生于德国。
从1959年到1963年，克鲁伯格在法兰克福约翰-沃尔夫冈-歌德大学学习物理，1962年获得中级文凭，1969年在达姆施塔特技术大学获得博士学位。
1988年，克鲁伯格在尤利西研究中心研究并发现巨磁电阻效应。
1992年被任命为科隆大学兼任教授。
2004年在研究中心工作32年后退休，但仍继续工作，直到2018年逝世。
巨磁电阻效应是指当铁磁材料（Ferromagnetic）和非磁性金属（Non-Magnetic Metal）层交替组合成的材料，在既使微弱的磁场作用下铁磁层的电阻突然巨幅下降的现象。
特别值得注意的是，如果相邻材料中铁磁层的磁化方向平行的1时候，电阻会变得很低；而当铁磁层的磁化方向相反的时候电阻则会变得很大。
电阻值的这种变化是由于不同自旋的电子在单层磁化材料中的散射性质不同而造成的。
早在1988年，费尔和克鲁伯格就各自独立发现了这一特殊现象：非常弱小的磁场变化就能导致磁性材料发生非常显著的电阻变化。
物理光学 第1章 光的电磁理论
r2
E r
1 v2
2E 0 t 2
2）时谐球面波方程（只考虑电矢量）：
E E0 cost k r
脉冲波可视为大量不同频率定态波的叠加。
均匀平面波：面波上的场矢量都相等的平面波。
时谐平面波：如果均匀平面波的空间各点的电磁振动均以同一频率 随时间作简谐振动，则称为时谐均匀平面波，简称时谐平面波。
二、平面波的特性及参量
1、时谐平面波
(1)波动方程
设均匀平面波沿+z方向传播，则波动方程为
2E
1 v2
H H expit
（1-33）
式中：H H0 exp i kz 0
2）时谐平面波的能流密度
S EH
3）时谐平面光波的强度
I 1 T
T
Sdt
0
1 2
Re
E
*
H
（1-34)
4）沿任意方向 z传播的时谐平面波(波矢为k)在波 面Σ上任一点P处的场振动 设任一点P位矢为 r ,它在k方向的投影为OP z
H ey H0 cos(t kz)
3) 坡印廷矢量（电磁能流密度矢量）
(1-6a) (1-6b)
SE H
(1-7)
4) 光强度
I 1
Sdt
1
E Hdt
0
0
(1-8)
（导出参§1.2 ）
本节要点(§1.1 电磁波谱及电磁场基本方程)
一、电磁波谱
1、全波谱：无→微→红外→可见→紫外→ X → γ
5）与光程对应的相位变化：
2
（1-29）
polarization
Ey = E2 cos(ωt − βz )
The University of Texas at Dallas
Erik Jonsson School PhoTEC
SNAPSHOT OF PLANE-POLARIZED PLANE WAVE
0
5
Z
10 15 1 0 X -1 0 -1 1
c C. D. Cantrell (03/2004)
2
2
The University of Texas at Dallas
Erik Jonsson School PhoTEC
ORTHOGONAL POLARIZATIONS (1) • For a plane wave, there are always 2 orthogonal states of polarization Simplest case: Orthogonal linear polarizations described by unit coordiˆ and y ˆ nate vectors x ˆ·y ˆ=0 ◦ Orthogonality: x ˆ·x ˆ=1=y ˆ·y ˆ ◦ Normalization: x ◦ Example of orthogonally polarized fields: ˆE1 cos(ωt − βz ), E1 = x ˆE2 cos(ωt − βz + δ ) E2 = y The important point: Waves with orthogonal polarizations do not interfere with one another • Example: In a “single-mode” fiber, there are really two modes, one for each of the two orthogonal polarizations These modes don’t have the same group velocity The difference in group velocities leads to polarization-mode dispersion, pulse spreading, and bandwidth limitations
光学的椭圆度 英文
光学的椭圆度英文
English:
Optical ellipsometry is a technique used to measure the polarization state of light after it interacts with a sample. The ellipsometry measurement provides information about the thickness, refractive index, and surface roughness of a sample. The optical ellipsometry is particularly useful in characterizing thin film materials, such as semiconductors, dielectrics, and metals. By analyzing the changes in the polarization state of light as it interacts with the sample, optical ellipsometry can provide valuable insights into the optical and structural properties of materials.
中文翻译:
光学椭圆测量是一种用于测量光与样品相互作用后的偏振状态的技术。
椭圆测量提供有关样品厚度、折射率和表面粗糙度的信息。
光学椭圆测量在表征薄膜材料（如半导体、介质和金属）方面特别有用。
通过分析光与样品相互作用时偏振状态的变化，光学椭圆测量可以为材料的光学和结构特性提供宝贵的见解。
N=4 Super-Yang-Mills Theory, QCD and Collider Physics
a rXiv:h ep-th/04121v12O ct24SLAC–PUB–10739,IPPP/04/59,DCPT/04/118,UCLA/04/TEP/40Saclay/SPhT–T04/116,hep-th/0410021October,2004N =4Super-Yang-Mills Theory,QCD and Collider Physics Z.Bern a L.J.Dixon b 1 D.A.Kosower c a Department of Physics &Astronomy,UCLA,Los Angeles,CA 90095-1547,USA b SLAC,Stanford University,Stanford,CA 94309,USA,and IPPP,University of Durham,Durham DH13LE,England c Service de Physique Th´e orique,CEA–Saclay,F-91191Gif-sur-Yvette cedex,France1Introduction and Collider Physics MotivationMaximally supersymmetric (N =4)Yang-Mills theory (MSYM)is unique in many ways.Its properties are uniquely specified by the gauge group,say SU(N c ),and the value of the gauge coupling g .It is conformally invariant for any value of g .Although gravity is not present in its usual formulation,MSYMis connected to gravity and string theory through the AdS/CFT correspon-dence[1].Because this correspondence is a weak-strong coupling duality,it is difficult to verify quantitatively for general observables.On the other hand, such checks are possible and have been remarkably successful for quantities protected by supersymmetry such as BPS operators[2],or when an additional expansion parameter is available,such as the number offields in sequences of composite,large R-charge operators[3,4,5,6,7,8].It is interesting to study even more observables in perturbative MSYM,in order to see how the simplicity of the strong coupling limit is reflected in the structure of the weak coupling expansion.The strong coupling limit should be even simpler when the large-N c limit is taken simultaneously,as it corresponds to a weakly-coupled supergravity theory in a background with a large radius of curvature.There are different ways to study perturbative MSYM.One approach is via computation of the anomalous dimensions of composite,gauge invariant operators[1,3,4,5,6,7,8].Another possibility[9],discussed here,is to study the scattering amplitudes for(regulated)plane-wave elementaryfield excitations such as gluons and gluinos.One of the virtues of the latter approach is that perturbative MSYM scat-tering amplitudes share many qualitative properties with QCD amplitudes in the regime probed at high-energy colliders.Yet the results and the computa-tions(when organized in the right way)are typically significantly simpler.In this way,MSYM serves as a testing ground for many aspects of perturbative QCD.MSYM loop amplitudes can be considered as components of QCD loop amplitudes.Depending on one’s point of view,they can be considered either “the simplest pieces”(in terms of the rank of the loop momentum tensors in the numerator of the amplitude)[10,11],or“the most complicated pieces”in terms of the degree of transcendentality(see section6)of the special functions entering thefinal results[12].As discussed in section6,the latter interpreta-tion links recent three-loop anomalous dimension results in QCD[13]to those in the spin-chain approach to MSYM[5].The most direct experimental probes of short-distance physics are collider experiments at the energy frontier.For the next decade,that frontier is at hadron colliders—Run II of the Fermilab Tevatron now,followed by startup of the CERN Large Hadron Collider in2007.New physics at colliders always contends with Standard Model backgrounds.At hadron colliders,all physics processes—signals and backgrounds—are inherently QCD processes.Hence it is important to be able to predict them theoretically as precisely as possi-ble.The cross section for a“hard,”or short-distance-dominated processes,can be factorized[14]into a partonic cross section,which can be computed order by order in perturbative QCD,convoluted with nonperturbative but measur-able parton distribution functions(pdfs).For example,the cross section for producing a pair of jets(plus anything else)in a p¯p collision is given byσp¯p→jjX(s)= a,b1 0dx1dx2f a(x1;µF)¯f b(x2;µF)׈σab→jjX(sx1x2;µF,µR;αs(µR)),(1)where s is the squared center-of-mass energy,x1,2are the longitudinal(light-cone)fractions of the p,¯p momentum carried by partons a,b,which may be quarks,anti-quarks or gluons.The experimental definition of a jet is an in-volved one which need not concern us here.The pdf f a(x,µF)gives the prob-ability forfinding parton a with momentum fraction x inside the proton; similarly¯f b is the probability forfinding parton b in the antiproton.The pdfs depend logarithmically on the factorization scaleµF,or transverse resolution with which the proton is examined.The Mellin moments of f a(x,µF)are for-ward matrix elements of leading-twist operators in the proton,renormalized at the scaleµF.The quark distribution function q(x,µ),for example,obeys 10dx x j q(x,µ)= p|[¯qγ+∂j+q](µ)|p .2Ingredients for a NNLO CalculationMany hadron collider measurements can benefit from predictions that are accurate to next-to-next-to-leading order(NNLO)in QCD.Three separate ingredients enter such an NNLO computation;only the third depends on the process:(1)The experimental value of the QCD couplingαs(µR)must be determinedat one value of the renormalization scaleµR(for example m Z),and its evolution inµR computed using the3-loopβ-function,which has been known since1980[15].(2)The experimental values for the pdfs f a(x,µF)must be determined,ide-ally using predictions at the NNLO level,as are available for deep-inelastic scattering[16]and more recently Drell-Yan production[17].The evolu-tion of pdfs inµF to NNLO accuracy has very recently been completed, after a multi-year effort by Moch,Vermaseren and Vogt[13](previously, approximations to the NNLO kernel were available[18]).(3)The NNLO terms in the expansion of the partonic cross sections must becomputed for the hadronic process in question.For example,the parton cross sections for jet production has the expansion,ˆσab→jjX=α2s(A+αs B+α2s C+...).(2)The quantities A and B have been known for over a decade[19],but C has not yet been computed.Figure 1.LHC Z production [22].•real ×real:וvirtual ×real:וvirtual ×virtual:וdoubly-virtual ×real:×Figure 2.Purely gluonic contributionsto ˆσgg →jjX at NNLO.Indeed,the NNLO terms are unknown for all but a handful of collider puting a wide range of processes at NNLO is the goal of a large amount of recent effort in perturbative QCD [20].As an example of the im-proved precision that could result from this program,consider the production of a virtual photon,W or Z boson via the Drell-Yan process at the Tevatron or LHC.The total cross section for this process was first computed at NNLO in 1991[21].Last year,the rapidity distribution of the vector boson also be-came available at this order [17,22],as shown in fig.1.The rapidity is defined in terms of the energy E and longitudinal momentum p z of the vector boson in the center-of-mass frame,Y ≡1E −p z .It determines where the vector boson decays within the detector,or outside its acceptance.The rapidity is sensitive to the x values of the incoming partons.At leading order in QCD,x 1=e Y m V /√s ,where m V is the vector boson mass.The LHC will produce roughly 100million W s and 10million Z s per year in detectable (leptonic)decay modes.LHC experiments will be able to map out the curve in fig.1with exquisite precision,and use it to constrain the parton distributions —in the same detectors that are being used to search for new physics in other channels,often with similar q ¯q initial states.By taking ratios of the other processes to the “calibration”processes of single W and Z production,many experimental uncertainties,including those associated with the initial state parton distributions,drop out.Thus fig.1plays a role as a “partonic luminosity monitor”[23].To get the full benefit of the remarkable experimental precision,though,the theory uncertainty must approach the 1%level.As seen from the uncertainty bands in the figure,this precision is only achievable at NNLO.The bands are estimated by varying the arbitrary renormalization and factorization scales µR and µF (set to a common value µ)from m V /2to 2m V .A computation to all orders in αs would have no dependence on µ.Hence the µ-dependence of a fixed order computation is related to the size of the missing higher-order terms in the series.Althoughsub-1%uncertainties may be special to W and Z production at the LHC, similar qualitative improvements in precision will be achieved for many other processes,such as di-jet production,as the NNLO terms are completed.Even within the NNLO terms in the partonic cross section,there are several types of ingredients.This feature is illustrated infig.2for the purely gluonic contributions to di-jet production,ˆσgg→jjX.In thefigure,individual Feynman graphs stand for full amplitudes interfered(×)with other amplitudes,in order to produce contributions to a cross section.There may be2,3,or4partons in thefinal state.Just as in QED it is impossible to define an outgoing electron with no accompanying cloud of soft photons,also in QCD sensible observables require sums overfinal states with different numbers of partons.Jets,for example,are defined by a certain amount of energy into a certain conical region.At leading order,that energy typically comes from a single parton, but at NLO there may be two partons,and at NNLO three partons,within the jet cone.Each line infig.2results in a cross-section contribution containing severe infrared divergences,which are traditionally regulated by dimensional regula-tion with D=4−2ǫ.Note that this regulation breaks the classical conformal invariance of QCD,and the classical and quantum conformal invariance of N=4super-Yang-Mills theory.Each contribution contains poles inǫranging from1/ǫ4to1/ǫ.The poles in the real contributions come from regions ofphase-space where the emitted gluons are soft and/or collinear.The poles in the virtual contributions come from similar regions of virtual loop integra-tion.The virtual×real contribution obviously has a mixture of the two.The Kinoshita-Lee-Nauenberg theorem[24]guarantees that the poles all cancel in the sum,for properly-defined,short-distance observables,after renormal-izing the coupling constant and removing initial-state collinear singularities associated with renormalization of the pdfs.A critical ingredient in any NNLO prediction is the set of two-loop ampli-tudes,which enter the doubly-virtual×real interference infig.2.Such ampli-tudes require dimensionally-regulated all-massless two-loop integrals depend-ing on at least one dimensionless ratio,which were only computed beginning in 1999[25,26,27].They also receive contributions from many Feynman diagrams, with lots of gauge-dependent cancellations between them.It is of interest to develop more efficient,manifestly gauge-invariant methods for combining di-agrams,such as the unitarity or cut-based method successfully applied at one loop[10]and in the initial two-loop computations[28].i,ij+ i iFigure3.Illustration of soft-collinear(left)and pure-collinear(right)one-loop di-vergences.3N=4Super-Yang-Mills Theory as a Testing Ground for QCDN=4super-Yang-Mills theory serves an excellent testing ground for pertur-bative QCD methods.For n-gluon scattering at tree level,the two theories in fact give identical predictions.(The extra fermions and scalars of MSYM can only be produced in pairs;hence they only appear in an n-gluon ampli-tude at loop level.)Therefore any consequence of N=4supersymmetry,such as Ward identities among scattering amplitudes[29],automatically applies to tree-level gluonic scattering in QCD[30].Similarly,at tree level Witten’s topological string[31]produces MSYM,but implies twistor-space localization properties for QCD tree amplitudes.(Amplitudes with quarks can be related to supersymmetric amplitudes with gluinos using simple color manipulations.)3.1Pole Structure at One and Two LoopsAt the loop-level,MSYM becomes progressively more removed from QCD. However,it can still illuminate general properties of scattering amplitudes,in a calculationally simpler arena.Consider the infrared singularities of one-loop massless gauge theory amplitudes.In dimensional regularization,the leading singularity is1/ǫ2,arising from virtual gluons which are both soft and collinear with respect to a second gluon or another massless particle.It can be char-acterized by attaching a gluon to any pair of external legs of the tree-level amplitude,as in the left graph infig.3.Up to color factors,this leading diver-gence is the same for MSYM and QCD.There are also purely collinear terms associated with individual external lines,as shown in the right graph infig.3. The pure-collinear terms have a simpler form than the soft terms,because there is less tangling of color indices,but they do differ from theory to theory.The full result for one-loop divergences can be expressed as an operator I(1)(ǫ) which acts on the color indices of the tree amplitude[32].Treating the L-loop amplitude as a vector in color space,|A(L)n ,the one-loop result is|A(1)n =I(1)(ǫ)|A(0)n +|A(1),finn ,(3)where |A (1),fin nis finite as ǫ→0,and I (1)(ǫ)=1Γ(1−ǫ)n i =1n j =i T i ·T j 1T 2i 1−s ij ǫ,(4)where γis Euler’s constant and s ij =(k i +k j )2is a Mandelstam invariant.The color operator T i ·T j =T a i T a j and factor of (µ2R /(−s ij ))ǫarise from softgluons exchanged between legs i and j ,as in the left graph in fig.3.The pure 1/ǫpoles terms proportional to γi have been written in a symmetric fashion,which slightly obscures the fact that the color structure is actually simpler.We can use the equation which represents color conservation in the color-space notation, n j =1T j =0,to simplify the result.At order 1/ǫwe may neglect the (µ2R /(−s ij ))ǫfactor in the γi terms,and we have n j =i T i ·T j γi /T 2i =−γi .So the color structure of the pure 1/ǫterm is actually trivial.For an n -gluon amplitude,the factor γi is set equal to its value for gluons,which turns out to be γg =b 0,the one-loop coefficient in the β-function.Hence the pure-collinear contribution vanishes for MSYM,but not for QCD.The divergences of two-loop amplitudes can be described in the same for-malism [32].The relation to soft-collinear factorization has been made more transparent by Sterman and Tejeda-Yeomans,who also predicted the three-loop behavior [33].Decompose the two-loop amplitude |A (2)n as|A (2)n =I (2)(ǫ)|A (0)n +I (1)(ǫ)|A (1)n +|A (2),fin n,(5)where |A (2),fin n is finite as ǫ→0and I (2)(ǫ)=−1ǫ+e −ǫγΓ(1−2ǫ)ǫ+K I (1)(2ǫ)+e ǫγT 2i µ22C 2A ,(8)where C A =N c is the adjoint Casimir value.The quantity ˆH(2)has non-trivial,but purely subleading-in-N c ,color structure.It is associated with soft,rather than collinear,momenta [37,33],so it is theory-independent,up to color factors.An ansatz for it for general n has been presented recently [38].3.2Recycling Cuts in MSYMAn efficient way to compute loop amplitudes,particularly in theories with a great deal of supersymmetry,is to use unitarity and reconstruct the am-plitude from its cuts [10,38].For the four-gluon amplitude in MSYM,the two-loop structure,and much of the higher-loop structure,follows from a sim-ple property of the one-loop two-particle cut in this theory.For simplicity,we strip the color indices offof the four-point amplitude A (0)4,by decomposing it into color-ordered amplitudes A (0)4,whose coefficients are traces of SU(N c )generator matrices (Chan-Paton factors),A (0)4(k 1,a 1;k 2,a 2;k 3,a 3;k 4,a 4)=g 2 ρ∈S 4/Z 4Tr(T a ρ(1)T a ρ(2)T a ρ(3)T a ρ(4))×A (0)4(k ρ(1),k ρ(2),k ρ(3),k ρ(4)).(9)The two-particle cut can be written as a product of two four-point color-ordered amplitudes,summed over the pair of intermediate N =4states S,S ′crossing the cut,which evaluates toS,S ′∈N =4A (0)4(k 1,k 2,ℓS ,−ℓ′S ′)×A (0)4(ℓ′S ′,−ℓS ,k 3,k 4)=is 12s 23A (0)4(k 1,k 2,k 3,k 4)×1(ℓ−k 3)2,(10)where ℓ′=ℓ−k 1−k 2.This equation is also shown in fig.4.The scalar propagator factors in eq.(10)are depicted as solid vertical lines in the figure.The dashed line indicates the cut.Thus the cut reduces to the cut of a scalar box integral,defined byI D =4−2ǫ4≡ d 4−2ǫℓℓ2(ℓ−k 1)2(ℓ−k 1−k 2)2(ℓ+k 4)2.(11)One of the virtues of eq.(10)is that it is valid for arbitrary external states in the N =4multiplet,although only external gluons are shown in fig.4.Therefore it can be re-used at higher loop order,for example by attaching yet another tree to the left.N =41234=i s 12s 231234Figure 4.The one-loop two-particle cuts for the four-point amplitude in MSYM reduce to the tree amplitude multiplied by a cut scalar box integral (for any set of four external states).i 2s 12s121234+s 121234+perms Figure 5.The two-loop gg →gg amplitude in MSYM [11,39].The blob on theright represents the color-ordered tree amplitude A (0)4.(The quantity s 12s 23A (0)4transforms symmetrically under gluon interchange.)In the the brackets,black linesare kinematic 1/p 2propagators,with scalar (φ3)vertices.Green lines are color δab propagators,with structure constant (f abc )vertices.The permutation sum is over the three cyclic permutations of legs 2,3,4,and makes the amplitude Bose symmetric.At two loops,the simplicity of eq.(10)made it possible to compute the two-loop gg →gg scattering amplitude in that theory (in terms of specific loop integrals)in 1997[11],four years before the analogous computations in QCD [36,37].All of the loop momenta in the numerators of the Feynman di-agrams can be factored out,and only two independent loop integrals appear,the planar and nonplanar scalar double box integrals.The result can be writ-ten in an appealing diagrammatic form,fig.5,where the color algebra has the same form as the kinematics of the loop integrals [39].At higher loops,eq.(10)leads to a “rung rule”[11]for generating a class of (L +1)-loop contributions from L -loop contributions.The rule states that one can insert into a L -loop contribution a rung,i.e.a scalar propagator,transverse to two parallel lines carrying momentum ℓ1+ℓ2,along with a factor of i (ℓ1+ℓ2)2in the numerator,as shown in fiing this rule,one can construct recursively the external and loop-momentum-containing numerators factors associated with every φ3-type diagram that can be reduced to trees by a sequence of two-particle cuts,such as the diagram in fig.7a .Such diagrams can be termed “iterated 2-particle cut-constructible,”although a more compact notation might be ‘Mondrian’diagrams,given their resemblance to Mondrian’s paintings.Not all diagrams can be computed in this way.The diagram in fig.7b is not in the ‘Mondrian’class,so it cannot be determined from two-particle cuts.Instead,evaluation of the three-particle cuts shows that it appears with a non-vanishing coefficient in the subleading-color contributions to the three-loop MSYM amplitude.ℓ1ℓ2−→i (ℓ1+ℓ2)2ℓ1ℓ2Figure 6.The rung rule for MSYM.(a)(b)Figure 7.(a)Example of a ‘Mondrian’diagram which can be determined re-cursively from the rung rule.(b)Thefirst non-vanishing,non-Mondrian dia-grams appear at three loops in nonplanar,subleading-color contributions.4Iterative Relation in N =4Super-Yang-Mills TheoryAlthough the two-loop gg →gg amplitude in MSYM was expressed in terms of scalar integrals in 1997[11],and the integrals themselves were computed as a Laurent expansion about D =4in 1999[25,26],the expansion of the N =4amplitude was not inspected until last fall [9],considerably after similar investigations for QCD and N =1super-Yang-Mills theory [36,37].It was found to have a quite interesting “iterative”relation,when expressed in terms of the one-loop amplitude and its square.At leading color,the L -loop gg →gg amplitude has the same single-trace color decomposition as the tree amplitude,eq.(9).Let M (L )4be the ratio of this leading-color,color-ordered amplitude to the corresponding tree amplitude,omitting also several conventional factors,A (L ),N =4planar 4= 2e −ǫγg 2N c2 M (1)4(ǫ) 2+f (ǫ)M (1)4(2ǫ)−12(ζ2)2is replaced by approximately sixpages of formulas (!),including a plethora of polylogarithms,logarithms and=+f(ǫ)−12(ζ2)2+O(ǫ)f(ǫ)=−(ζ2+ǫζ3+ǫ2ζ4+...)Figure8.Schematic depiction of the iterative relation(13)between two-loop and one-loop MSYM amplitudes.polynomials in ratios of invariants s/t,s/u and t/u[37].The polylogarithm is defined byLi m(x)=∞i=1x i t Li m−1(t),Li1(x)=−ln(1−x).(14)It appears with degree m up to4at thefinite,orderǫ0,level;and up to degree4−i in the O(ǫ−i)terms.In the case of MSYM,identities relating these polylogarithms are needed to establish eq.(13).Although the O(ǫ0)term in eq.(13)is miraculously simple,as noted above the behavior of the pole terms is not a miracle.It is dictated in general terms by the cancellation of infrared divergences between virtual corrections and real emission[24].Roughly speaking,for this cancellation to take place,the virtual terms must resemble lower-loop amplitudes,and the real terms must resemble lower-point amplitudes,in the soft and collinear regions of loop or phase-space integration.At the level of thefinite terms,the iterative relation(13)can be understood in the Regge/BFKL limit where s≫t,because it then corresponds to expo-nentiation of large logarithms of s/t[40].For general values of s/t,however, there is no such argument.The relation is special to D=4,where the theory is conformally invariant. That is,the O(ǫ1)remainder terms cannot be simplified significantly.For ex-ample,the two-loop amplitude M(2)4(ǫ)contains at O(ǫ1)all three independent Li5functions,Li5(−s/u),Li5(−t/u)and Li5(−s/t),yet[M(1)4(ǫ)]2has only the first two of these[9].The relation is also special to the planar,leading-color limit.The subleading color-components of thefinite remainder|A(2),finn defined by eq.(5)show no significant simplification at all.For planar amplitudes in the D→4limit,however,there is evidence that an identical relation also holds for an arbitrary number n of external legs, at least for certain“maximally helicity-violating”(MHV)helicity amplitudes. This evidence comes from studying the limits of two-loop amplitudes as two of the n gluon momenta become collinear[9,38,41].(Indeed,it was by analyzing these limits that the relation for n=4wasfirst uncovered.)The collinear limits turn out to be consistent with the same eq.(13)with M4replaced by M n everywhere[9],i.e.M(2)n(ǫ)=12(ζ2)2+O(ǫ).(15)The collinear consistency does not constitute a proof of eq.(15),but in light of the remarkable properties of MSYM,it would be surprising if it were not true in the MHV case.Because the direct computation of two-loop amplitudes for n>4seems rather difficult,it would be quite interesting to try to examine the twistor-space properties of eq.(15),along the lines of refs.[31,42].(The right-hand-side of eq.(15)is not completely specified at order1/ǫandǫ0for n>4.The reason is that the orderǫandǫ2terms in M(1)n(ǫ),which contribute to thefirst term in eq.(15)at order1/ǫandǫ0,contain the D=6−2ǫpentagon integral[43],which is not known in closed form.On the other hand, the differential equations this integral satisfies may suffice to test the twistor-space behavior.Or one may examine just thefinite remainder M(L),finn definedvia eq.(5).)It may soon be possible to test whether an iterative relation for planar MSYM amplitudes extends to three loops.An ansatz for the three-loop planar gg→gg amplitude,shown infig.9,was provided at the same time as the two-loop re-sult,in1997[11].The ansatz is based on the“rung-rule”evaluation of the iterated2-particle cuts,plus the3-particle cuts with intermediate states in D=4;the4-particle cuts have not yet been verified.Two integrals,each be-ginning at O(ǫ−6),are required to evaluate the ansatz in a Laurent expansion about D=4.(The other two integrals are related by s↔t.)The triple ladder integral on the top line offig.9was evaluated last year by Smirnov,all the way through O(ǫ0)[44].Evaluation of the remaining integral,which contains a factor of(ℓ+k4)2in the numerator,is in progress[45];all the terms through O(ǫ−2)agree with predictions[33],up to a couple of minor corrections.5Significance of Iterative Behavior?It is not yet entirely clear why the two-loop four-point amplitude,and prob-ably also the n-point amplitudes,have the iterative structure(15).However, one can speculate that it is from the need for the perturbative series to=i3s12s212+s223+2s12(ℓ+k4)+2s23(ℓ+k1)21Figure9.Graphical representation of the three-loop amplitude for MSYM in the planar limit.be summable into something which becomes“simple”in the planar strong-coupling limit,since that corresponds,via AdS/CFT,to a weakly-coupled supergravity theory.The fact that the relation is special to the conformal limit D→4,and to the planar limit,backs up this speculation.Obviously it would be nice to have some more information at three loops.There have been other hints of an iterative structure in the four-point correlation func-tions of chiral primary(BPS)composite operators[46],but here also the exact structure is not yet clear.Integrability has played a key role in recent higher-loop computations of non-BPS spin-chain anomalous dimensions[4,5,6,8].By imposing regularity of the BMN‘continuum’limit[3],a piece of the anoma-lous dimension matrix has even been summed to all orders in g2N c in terms of hypergeometric functions[7].The quantities we considered here—gauge-invariant,but dimensionally regularized,scattering amplitudes of color non-singlet states—are quite different from the composite color-singlet operators usually treated.Yet there should be some underlying connection between the different perturbative series.6Aside:Anomalous Dimensions in QCD and MSYMAs mentioned previously,the set of anomalous dimensions for leading-twist operators was recently computed at NNLO in QCD,as the culmination of a multi-year effort[13]which is central to performing precise computations of hadron collider cross sections.Shortly after the Moch,Vermaseren and Vogt computation,the anomalous dimensions in MSYM were extracted from this result by Kotikov,Lipatov,Onishchenko and Velizhanin[12].(The MSYM anomalous dimensions are universal;supersymmetry implies that there is only one independent one for each Mellin moment j.)This extraction was non-trivial,because MSYM contains scalars,interacting through both gauge and Yukawa interactions,whereas QCD does not.However,Kotikov et al.noticed, from comparing NLO computations in both leading-twist anomalous dimen-sions and BFKL evolution,that the“most complicated terms”in the QCDcomputation always coincide with the MSYM result,once the gauge group representation of the fermions is shifted from the fundamental to the adjoint representation.One can define the“most complicated terms”in the x-space representation of the anomalous dimensions—i.e.the splitting kernels—as follows:Assign a logarithm or factor ofπa transcendentality of1,and a polylogarithm Li m or factor ofζm=Li m(1)a transcendentality of m.Then the most complicated terms are those with leading transcendentality.For the NNLO anomalous dimensions,this turns out to be transcendentality4.(This rule for extracting the MSYM terms from QCD has also been found to hold directly at NNLO,for the doubly-virtual contributions[38].)Strikingly,the NNLO MSYM anomalous dimension obtained for j=4by this procedure agrees with a previous result derived by assuming an integrable structure for the planar three-loop contribution to the dilatation operator[5].7Conclusions and OutlookN=4super-Yang-Mills theory is an excellent testing ground for techniques for computing,and understanding the structure of,QCD scattering amplitudes which are needed for precise theoretical predictions at high-energy colliders. One can even learn something about the structure of N=4super-Yang-Mills theory in the process,although clearly there is much more to be understood. Some open questions include:Is there any AdS/CFT“dictionary”for color non-singlet states,like plane-wave gluons?Can one recover composite operator correlation functions from any limits of multi-point scattering amplitudes?Is there a better way to infrared regulate N=4supersymmetric scattering amplitudes,that might be more convenient for approaching the AdS/CFT correspondence,such as compactification on a three-sphere,use of twistor-space,or use of coherent external states?Further investigations of this arena will surely be fruitful.AcknowledgementsWe are grateful to the organizers of Strings04for putting together such a stim-ulating meeting.This research was supported by the US Department of En-ergy under contracts DE-FG03-91ER40662(Z.B.)and DE-AC02-76SF00515 (L.J.D.),and by the Direction des Sciences de la Mati`e re of the Commissariat `a l’Energie Atomique of France(D.A.K.).。
Polarization of Light
Polarization of Light光的偏振现象光是一种电磁波，它具有波动性质。
然而，当光通过某些介质或物体时，它的波动方向会发生改变，这种现象被称为光的偏振。
光的偏振是光学中一个重要的现象，它不仅在科学研究中有着广泛的应用，而且在日常生活中也有着重要的意义。
光的偏振现象最早由英国科学家哈克斯比发现。
他通过实验证明了光可以具有不同的振动方向，从而揭示了光的偏振现象。
在哈克斯比的实验中，他利用了一种称为偏振片的器件，通过旋转偏振片的方向，他观察到光的强度发生了明显的变化。
这表明，光的偏振是由光波的振动方向决定的。
光的偏振现象可以通过光的波动性质来解释。
光是由电场和磁场垂直于传播方向的振动波动组成的。
在自然光中，电场的振动方向是随机的，因此光是无偏振的。
然而，当光通过某些介质或物体时，电场的振动方向会受到限制，从而使光具有偏振性质。
光的偏振可以分为线偏振和圆偏振两种类型。
线偏振光是指光的电场振动方向只沿着一条直线，而圆偏振光则是指光的电场振动方向沿着一个圆形轨迹。
线偏振光和圆偏振光是光的两种常见偏振状态，它们在科学研究和技术应用中都有着重要的作用。
光的偏振现象在科学研究中有着广泛的应用。
例如，在材料科学中，通过研究光的偏振现象可以了解材料的结构和性质。
通过光的偏振现象，科学家可以推断出材料中的分子或晶格的排列方式，从而揭示材料的内部结构。
此外，光的偏振还被应用于光学显微镜和光学成像技术中，以提高图像的清晰度和分辨率。
光的偏振现象在日常生活中也有着重要的意义。
例如，在太阳光中，由于光的偏振现象，我们可以使用偏振片来减少反射和散射，从而降低眩光。
这在驾驶汽车或户外活动中非常有用。
此外，光的偏振还被应用于液晶显示器和3D电影技术中，以实现图像的清晰和立体效果。
然而，光的偏振现象也存在一些问题和挑战。
例如，当光通过大气层时，由于大气中的颗粒和分子的散射作用，光的偏振状态会发生改变，从而影响光的传播和接收。
伯克利 四大力学
伯克利四大力学
伯克利四大力学是指17世纪爱尔兰哲学家乔治·伯克利提出的
一种哲学理论，也被称为主观唯心主义。
这一理论包括四个基本观点：
1. 色力学（color perception）：伯克利认为颜色是一种主观感知，只存在于我们的意识中。
他否定了物质世界中存在着独立的颜色。
2. 触力学（tactual perception）：伯克利认为触觉也是一种主
观感知，与颜色一样，只存在于我们的意识中。
他否定了物质世界中存在着独立的触觉。
3. 空间力学（spatial perception）：伯克利认为空间和距离也
是一种主观感知，只存在于我们的意识中。
他否定了物质世界中存在着独立的空间和距离。
4. 移动力学（motion perception）：伯克利认为运动也是一种
主观感知，只存在于我们的意识中。
他否定了物质世界中存在着真正的运动。
伯克利四大力学可以被认为是一种反对物质实在性的哲学观点，它挑战了我们对物质世界的常识认识，主张我们只能通过我们的感知去观察和理解世界。
这一理论对西方哲学和认识论产生了深远的影响。
2004诺贝尔物理学奖揭晓
• 如图所示，在绳下端挂一质量为m的物体， 用力F拉绳使悬绳偏离竖直方向α角，且方 向固定，当拉力F与水平方向的夹角θ多大 时F有最小值？最小值是多少？
常规解析法：
• 以结点O为研究对象，画出受力图，建立坐标轴， 如图所示：根据平衡条件有： • Fcosθ－Tsinα＝0 • Fsinθ＋Tcosα－mg＝0 • 由两式消去Ｔ可得 • F＝mgsinα/cos (α－θ) • 所以当（α－θ）=0， • 即θ＝α时Ｆ有最小值，且 • Fmin＝ mgsinα。
•
2004诺贝尔物理学奖揭晓 诺贝尔物理学奖揭晓 新华社斯德哥尔摩１０ １０月 新华社斯德哥尔摩１０月５日电瑞典皇家 科学院５日宣布， ２００４年诺贝尔物 科学院５日宣布，将２００４年诺贝尔物 理学奖授予美国科学家戴维·格罗斯、戴 理学奖授予美国科学家戴维 格罗斯、 格罗斯 波利策和弗兰克·维尔切克 维·波利策和弗兰克 维尔切克，以表彰他们 波利策和弗兰克 维尔切克， 发现了粒子物理强相互作用理论中的渐近 自由现象。 自由现象。 格罗斯、 格罗斯、波利策和维尔切克目前分别在加 利福尼亚大学圣巴巴拉分校、 利福尼亚大学圣巴巴拉分校、加利福尼亚 理工学院和麻省理工学院工作， 理工学院和麻省理工学院工作，他们将分 １０００万瑞典克朗 约合１３０ 万瑞典克朗（ １３０万美 享１０００万瑞典克朗（约合１３０万美 的奖金。 元）的奖金。
Physical Optics01
以光的直线传播和反射、折射定律为基础，研究光学仪器 成象规律。
物理光学(physical optics)
以光的波动性和粒子性为基础，研究光现象基本规律。 • 波动光学——光的波动性：研究光的传输规律及其应用的学 科 • 量子光学——光的粒子性：研究光与物质相互作用规律及其 应用的学科
§7.1 General considerations
Purpose : 知道波的干涉现象； 知道简谐波的数学表达式； 理解波的叠加原理； 掌握相位差、路径差、光程差等基本概念； 掌握干涉加强和干涉减弱的条件
New words
Electromagnetic 电磁的；spectrum 光谱 interference 干涉 amplitude 振幅 phase difference 相位差；phenomena 现象 simple harmonic oscillation 简谐振动 frequency 频率 principle 原理 superposition 叠加 In phase 同相 out of phase 反相 constructive 加强的 destructive 相消的 irradiance 光强 optical path difference 光程差 coherence 相干
r n ,
r 2n 1
A 2 A1 (n 0,1, 2,)
constructive destructive
2
,
A 0 (n 0,1, 2,)
In another words: The phase difference
k r2 r1
then
A A1 A2 (n 0,1, 2,)
夸克世界中一个多彩色的发现 --2004年度诺贝尔物理学奖评述
夸克世界中一个多彩色的发现 --2004年度诺贝尔物理学奖评
述
郭振华;李宗红
【期刊名称】《宝鸡文理学院学报（自然科学版）》
【年(卷),期】2005(25)1
【摘要】2004年诺贝尔物理学奖授予美国科学家戴维·格罗斯(David J.Gross)、戴维·波利策(H.David Politzer)和弗兰克·维尔切克(Frank Wilczek),以表彰他们对粒子物理的强相互作用理论中的"渐近自由"现象的发现.渐近自由理论不仅解释了为什么夸克在高能状态下有近乎自由粒子的行为,而且也是对粒子物理的标准模型的一个重要贡献.
【总页数】4页(P77-80)
【作者】郭振华;李宗红
【作者单位】宝鸡文理学院,物理系,陕西,宝鸡,721007;宝鸡文理学院,物理系,陕西,宝鸡,721007
【正文语种】中文
【中图分类】O572.243;O572.33
【相关文献】
1.夸克世界的多彩发现 [J], 赵路
2.超导体和超流体理论的开创性贡献--2003年度诺贝尔物理学奖及其获得者评述[J], 郭振华;李宗红
3.巨磁电阻效应的发现及其应用——2007年诺贝尔物理学奖评述 [J], 卢森锴;陈远英
4.2007年度诺贝尔物理学奖评介巨磁电阻效应的发现和应用 [J], 于平;金晓峰
5.从物理发现到成功应用——兼谈2007年度诺贝尔物理学奖授予巨磁电阻效应发现者 [J], 韩秀峰;刘东屏;温振超
因版权原因，仅展示原文概要，查看原文内容请购买。
2005年诺贝尔物理学奖与光学频率梳
个坐标的纵模 ,其绝对频率可以表示为
f ( n) = nF +δ,
(1)
如图 1所示 ,这里 n是整数 ,δ是该纵模偏离对应坐
标的频率偏差 ,并有 δ < F. 由于激光脉冲的重复
频率 F通常在 100MHz左右 ,正好属于微波频率的
范围 ,因此如果将 F及 δ分别锁定到目前的微波原
·213·
© 1994-2008 China Academic Journal Electronic Publishing House. All rights reserved.
评 述
们将时间单位“秒 ”定义为“铯 - 133 原子基态的两 个超精细能级之间跃迁所对应辐射的 9 192 631 770 个周期的持续时间 ”[ 1 ] ,并一直沿用至今. 这一定义 下的时间精度达到了 10 - 15的量级 ,也是目前所有物 理量中最精确的基本单位. 由于时间与频率互为倒 数关系 ,因此在涉及频率的大量科学研究和技术应 用领域 ,如超精细光谱学 、全球定位系统 ( GPS) 、空 天飞行 、精密制导 、无线通讯等方面 ,高精度的频率 时间基准起着核心作用. 可以说以微波原子钟为基 础的时间频率标准 ,构成了现代科学技术大厦的基 石 ,而科学技术研究的不断发展 ,对时间频率的基准 又提出了更高的要求. 为了进一步提高其精度 ,早在 激光诞生后不久 ,人们就想到采用光学频率代替微 波钟作为新的时间基准的可能性 ,从原理上讲 ,由于 光频的频率在数百 THz量级 ,比 GHz的微波频率高 多个量级 ,因此原理上采用光钟可望得到优于 10 - 18 的准确性 ,这无疑会大大提高 GPS、深空导航 、基本 物理常数测量等内容的精度. 但一个巨大的障碍是 如何高精度地实现微波频率与光学频率的连接 ,多 年来一直是制约该项研究的主要瓶颈.
2004年诺贝尔物理奖介绍:渐近自由
2004年诺贝尔物理奖介绍：渐近自由
高崇寿
【期刊名称】《物理与工程》
【年(卷),期】2004(14)6
【摘要】描述粒子相互作用基本理论是标准模型,按照标准模型,强子是由夸克和反夸克通过色相互作用组成.色相互作用有一种特殊的性质:渐近自由.格罗斯、波利策和维尔切克由于确定地发现色相互作用的渐近自由性质获2004年诺贝尔物理奖.【总页数】3页(P2-4)
【作者】高崇寿
【作者单位】北京大学物理学院,北京,100871
【正文语种】中文
【中图分类】O4
【相关文献】
1.从2004年诺贝尔物理奖看一流大学的建设 [J], 杨福家
2.柳毅传书反对包办婚姻歌颂婚姻自由八仙过海借助法器宝物各人大显神通——2004年7月新邮介绍 [J], 乐明
3.对所谓“2004年中国与诺贝尔物理奖”一文读后 [J],
4.跑向自由--2004年诺贝尔物理学奖介绍 [J], 刘川
5.强相互作用量子色动力学的渐近自由——2004年诺贝尔物理奖成果简介 [J], 张肇西
因版权原因，仅展示原文概要，查看原文内容请购买。
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ˆ E2 E0 cos kx t k 2
(4) Elliptic polarized light If E1 E10 cos kx t 1 ˆ j ˆ E2 E20 cos kx t 2 k Then according to different 2 1 we will get different results. Generally the result is a ellipse.
E y E cos
I 2 cos 2 I0 E
2 Ey
I I 0 cos 2
Malus’s law
4. Polarization by reflection: Brewster’s lawn2 tan Nhomakorabea n1
Brewster’s law
The special angle of incidence that results in a reflected beam that is completely plane polarized is called Brewster angle. The refracted beam makes a 900 angle with this reflected beam . 0 B 2 90
n1 1.50
Stack of glass plates
5. Polarization by double refraction (birefringence) When an unpolarized light ray is incident on the crystal in certain directions, two refracted rays result! This phenomenon is called double refraction. Ordinary ray(O)follows the law of refraction; Extraordinary ray(E) does not follow the law of refraction. The two refraction rays are completely plane polarized along two perpendicular directions.
Any plane polarized wave can be resolved into two components along two mutually perpendicular directions chosen. We can model unpolarized light by two mutually perpendicular,collective, Incoherent oscillations.
How can the unpolarized light from a typical light source be polarized.
(2)Polarize by dichroic Some special material can absorb the one oscillation of light. If the oscillations of the transverse wave at a particular location are confined to a line,the wave is plane polarized.
3.Polarized by absorption and Malus’s law Unpolarized light can be polarized by selective absorption in passing through a polarizing sheet such as a polaroid. Half the light intensity is absorbed by the polarizing material and half is transmitted with a plane polarization parallel to the axis of the material.
(3) Partial polarized light If the part of one oscillation is absorbed, this kind of light is called partial polarized light.
Other types of polarized light can be created by judicious superposition of plane polarized light.
E1 E0 cos kx t ˆ j If ˆ E2 E0 cos kx t k Then E E1 E2
E0 cos kx t ˆ k j ˆ
This is a plane polarized light. Why the two waves do not interfere?
(4) Circular polarized light j Light vector: E E0 cos kx t ˆ E1 E0 cos kx t ˆ j If we look at x=0,then ˆ E E1 E2 E0 cos t ˆ sin t k j Such light is said to be right circularly polarized
The Brewster angle for an air-vater interface:
n2 1.33 tan B n1 1.00
B 53.1
0
The Brewster angle for an glass-air interface: n2 1.00 B 56.30 tan B
Polarization of light
1.Ploarization phenomena and Polarized light Only transverse waves can exhibit polarization.
2. Five polarized states of light (1)Unpolarized light The light wave emitted during a very short interval from an individual atom is polarized. Atoms in a typical light source all act independently of each other.