均匀磁场下二维拓扑绝缘体边缘态的多重Andreev反射研究  

Research on multiple Andreev reflections of edge states of atwo-dimensional topological insulator under uniform magnetic field

作　　者：杨雪[1] 吕博[1] YANG Xue;LÜBo(Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学,天津300350

出　　处：《现代电子技术》2024年第4期17-22,共6页Modern Electronics Technique

摘　　要：研究均匀磁场下的二维拓扑绝缘体在超导隧道结中的电压偏置约瑟夫森结的输运性质,电流-电压特性显示了马约拉纳束缚态的存在。在亚谐隙结构中,也可以观察到磁场对超导能隙的影响。研究结果表明,在S波超导体/正常金属/S波超导结的隧道谱中存在亚谐隙结构。透明度只影响超导结的零偏压电导值的大小,而不影响亚谐隙结构的位置。但是在磁场作用下,亚谐隙结构会发生变化,不再固定出现在特定位置。这一结果对应于拓扑螺旋态中超导和铁磁序之间的相互作用。The transport properties of voltage biased Josephson junctions of two-dimensional topological insulators in superconducting tunnel junctions under uniform magnetic field is researched.The current-voltage characteristics show the existence of Mayorana bound states.In the subharmonic gap structure,the effect of magnetic field on the superconducting energy gap can also be observed.The research results indicate that there is a subharmonic gapstructure in the tunnel spectrum of S-wave superconductors/normal metals/S-wave superconductors.The transparency can only affect the zero bias conductance value of the superconducting junction,and not affect the position of the subharmonic gap structure.However,under the action of magnetic field,the subharmonic gap structure will change and no longer appear fixed at a specific location.The results correspond to the interaction between superconductivity and ferromagnetic order in topological spiral states.

关 键 词：拓扑绝缘体 多重Andreev反射 超导隧道结 约瑟夫森结 亚谐隙结构 马约拉纳束缚态 S波超导体 准粒子波函数 

分 类 号：TN304.7-34[电子电信—物理电子学] TP304[自动化与计算机技术—计算机系统结构]