SN层间耦合及s+id对称性对高温超导体Josephson结电流的影响  

THE EFFECT OF THE SN PROXIMITY AND s+id SYMMETRY ON THE JOSEPHSON TUNNELING OF HIGH-T_c SUPERCONDUCTORS

作　　者：范晓娟[1,2] 孙学峰[1,2] 赵霞[1,2] 李晓光 

机构地区：[1]中国科学技术大学材料科学与工程系,合肥230026 [2]中国科学院固体物理研究所固体内耗与缺陷开放室,合肥230031

出　　处：《低温物理学报》2000年第1期52-55,共4页Low Temperature Physical Letters

摘　　要：本文考虑高温超导体YBa2Cu3Oy的结构特征,以S表示超导层,N表示非超导层,建立一个简单的SN双层高温超导体模型,用双层高温超导体模型构造成一个Josephson隧道结SNINS.我们从理论上用格林函数方法计算了c向结电流随层间耦合强度和s+id中s波分量的变化规律.结果发现随层间耦合的加强,结电流随温度的变化规律趋向于传统的AB理论.在一定的层间耦合强度下,随s波分量的减少,结电流逐渐减小,定性符合实验上确定的高温超导体d波对称性占主要地位的结论.对于YBCO体系,当层间耦合强度t⊥/Tc=1.9,s波分量ε=0.2时,计算结果与实验符合很好.The Josephson coupling between two identical high temperature superconductors was studied theoretically based on an SN (superconducting normal) bilayer model with s+id wave pairing in the S layer. It is indicated that due to the proximity effect as the interlayer hopping decreases, or as s wave component decreases, I\-cR\-n can be substantially reduced from the value described by the Ambegaokar Baratoff (AB) theory. Our theoretical result is in good agreement with the experiments.

关 键 词：SN层间耦合 高温超导体 Josephson结电流 

分 类 号：O511[理学—低温物理]