正常金属/绝缘层/s波超导隧道结中绝缘层对微分电导的影响  

Effect of the insulating layer on the differential conductance in the normal metal/ insulator/ s-wave superconductor tunnel junctions

作　　者：魏健文[1] 董正超[1] 

机构地区：[1]淮阴师范学院物理系,淮安223001

出　　处：《物理学报》2005年第5期2318-2324,共7页Acta Physica Sinica

基　　金：江苏省教育厅自然科学基金 (批准号 :0 4KJD14 0 0 3 6);国家自然科学基金 (批准号 :10 3 4712 9)资助的课题 .~~

摘　　要：在正常金属 /绝缘层 /s波超导隧道结 (NIS结 )中 ,以方势垒描述绝缘层对准粒子输运的影响 ,运用Bogoliubov-deGennes(BdG)方程、Blonder-Tinkham-Klapwijk(BTK)理论 ,计算了NIS隧道结中的准粒子输运系数和微分电导 .研究表明 ,微分电导随绝缘层厚度的变化呈振荡和衰减两种趋势 ,其振荡的周期和衰减的快慢均强烈地依赖于绝缘层的势垒值以及V=Δ0 /ｅ的偏压值 ,电导峰的高低及峰的位置与绝缘层厚度密切相关 ,显示了比δ势描述更为丰富多彩的隧道谱 .Making use of the square-potential barrier to describe the influence of the insulating layer on the quasi-particle transport in normal metal/insulator/superconductor (NIS) tunnel junctions, we calculate the quasi-particle transport coefficients and the differential conductance using the Bogoliubov-de Gennes (BdG) equation and Blonder-Tinkham-Klapwijk (BTK) theory. It is found that the change of the differential conductance with insulating layer thickness takes the form of the oscillation and attenuation, the period of oscillation and the speed of attenuation depend strongly on the potential magnitude of the insulating layer and the bias value, the height of the conductance peaks and their positions are related to the insulating layer thickness intimately. It is shown that the tunneling spectra are different from those described by the δ-potential.

关 键 词：NIS结 方势垒 微分电导 粒子输运 超导物理学 

分 类 号：O511[理学—低温物理]