2012约瑟夫森结

Home Search Collections Journals About Contact us My IOPscience

Structural and electrical characterization of ultra-thin SrTiO3 tunnel barriers grown over YBa2Cu3O7 electrodes for the development of high T c Josephson junctions

This content has been downloaded from IOPscience. Please scroll down to see the full text.

2012 Nanotechnology 23 495715

(/0957-4484/23/49/495715)

View the table of contents for this issue, or go to the journal homepage for more

Download details:

IP Address: 58.198.97.239

This content was downloaded on 24/05/2014 at 08:23

Please note that terms and conditions apply.

IOP P UBLISHING N ANOTECHNOLOGY Nanotechnology23(2012)495715(6pp)doi:10.1088/0957-4484/23/49/495715

Structural and electrical characterization of ultra-thin SrTiO3tunnel barriers grown over YBa2Cu3O7electrodes for the development of high T c Josephson junctions

L Avil´e s F´e lix1,M Sirena1,2,L A Ag¨uero Guzm´a n3,J Gonz´a lez Sutter3,

S Pons Vargas3,L B Steren2,4,R Bernard5,J Trastoy5,J E Villegas5,

J Bri´a tico5,N Bergeal6,J Lesueur6and G Faini7

1Centro At´o mico Bariloche,Instituto Balseiro—CNEA,Universidad Nacional de Cuyo,Avenida

Bustillo9500,8400Bariloche,Rio Negro,Argentina

2Consejo Nacional de Investigaciones Cient´ıficas y T´e cnicas,Avenida Rivadavia1917C1033AAJ

CABA,Argentina

3Universidad de Concepci´o n,Victoria631,2613Concepci´o n,Chile

4Centro At´o mico Constituyentes,Avenida Gral.Paz1499,San Mart´ın1650,Buenos Aires,Argentina

5Unit´e Mixte de Physique CNRS/THALES,Universit´e Paris Sud11,F-91767Palaiseau Cedex,France

6Laboratoire de Physique et d’Etude des Mat´e riaux,UMR8213/CNRS,ESPCI ParisTech,10rue

Vauquelin,Paris F-75005,France

7LPN-CNRS,Route de Nozay,F-91460Marcoussis,France

E-mail:lavilesf@

Received11August2012,infinal form24October2012

Published16November2012

Online at /Nano/23/495715

Abstract

The transport properties of ultra-thin SrTiO3(STO)layers grown over YBa2Cu3O7electrodes

were studied by conductive atomic force microscopy at the nano-scale.A very good control of

the barrier thickness was achieved during the deposition process.A phenomenological

approach was used to obtain critical parameters regarding the structural and electrical

properties of the system.The STO layers present an energy barrier of0.9eV and an

attenuation length of0.23nm,indicating very good insulating properties for the development

of high-quality Josephson junctions.

(Somefigures may appear in colour only in the online journal)

1.Introduction

A superconductor–insulator–superconductor Josephson junc-tion(JJ)is formed by two superconductor electrodes separated by a very thin insulating barrier composed of a few atomic layers[1].Cooper pairs canflow through this barrier thanks to the coupling of the superconducting electrodes.If a constant voltage is applied on the junction,an alternating current with a frequency in the range of1–1000GHz can be generated in the system[2].These two particular phenomena have many technological applications,such as the fabrication of a voltage standard[3],SQUIDs and other magnetic sensors[4], quantum computing(qubits)[5],and the fabrication of ultra-fast superconducting microelectronics based on rapid singleflux quantum logic[6].However,the fabrication of a homogeneous JJ array is complicated,especially for high