本征Josephson结的表面结的特性研究  

RESEARCH OF PROPERTIES OF SURFACE JUNCTION IN INTRINSIC JOSEPHSON JUNCTIONS

作　　者：杨莉[1] 许伟伟[1] 董晔[1] 郭大元[1] 尤立星[1] 阎生超[1] 吴培亨[1] 

机构地区：[1]南京大学电子科学与工程系超导电子研究所,南京210093

出　　处：《低温物理学报》2005年第2期154-158,共5页Low Temperature Physical Letters

基　　金：国家高技术研究发展计划课题 (项目编号 :2 0 0 2AA30 6 4 5 1;2 0 0 2AA30 6 181)资助项目 .~~

摘　　要：在用Bi2 Sr2 CaCu2 O8+δ(BSCCO)单晶制备本征结时,最上面的Cu O层由于受到所沉积的金属层的影响,其超导性能将发生退化,从而使得表面上两个邻近的Cu O层形成的表面结具有不同于内部本征结的性质.我们对表面结的I～V、Ic′～T、R～T等电运输特性进行了分析和研究,发现表面结的临界温度Tc 通常都比较低,而且临界电流随温度的变化关系也不同于正常本征结.并且利用旁路电阻的方法,成功观察到了被旁路后表面结的acJosephson效应.Superconductivity of the surface Cu-O layer is degraded since the deposited metal film on the top of IIJs affects the surface Cu-O layer during IIJs fabrication with Bi-2Sr-2CaCu-2O-{8+ δ }(BSCCO) single crystal. So characteristics of surface junction that consist of the surface Cu-O double layer differ greatly from those of IIJs. Analysis and research of surface junction in electrical transport characteristics such as I～V, I-c′～T and R～T , shows that the critical temperature T-c′ of surface junction is always lower than IIJs′, and the change of the critical current I-c′ of surface junction with rising of the temperature is different from that of IIJs. Moreover, we can observe the ac Josephson effect of surface junction by a shunted resistance on IIJs.

关 键 词：JOSEPHSON结 表面结 特性研究 JOSEPHSON效应 本征结 单晶制备 超导性能 临界温度 变化关系 临界电流 金属层 旁路 

分 类 号：O511.4[理学—低温物理]