Transport signatures of a junction between a quantum spin Hall system and a chiral topological superconductor
Transport signatures of a junction between a quantum spin Hall system and a chiral topological superconductor
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DOI：
10.1103/physrevb.101.235308
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发表时间：
2020-06
影响因子：
3.7
通讯作者：
E. Novik;B. Trauzettel;P. Recher
中科院分区：
文献类型：
--
作者：
E. Novik;B. Trauzettel;P. Recher
我们研究了由具有螺旋边缘态的量子自旋Hall（QSH）系统和具有手征Majorana边缘模的二维（2D）手征拓扑超导体（TSC）构成的正常超导体（NS）结的输运。我们采用一个二维扩展的四带模型的碲化汞基量子威尔斯在磁场（塞曼）场和$s$波超导。我们使用Bogoliubov-de Gennes散射形式主义，这种结构提供了一个惊人的二维TSC的传输信号。作为样本宽度（或费米能量）的函数，电导共振经历$2{e}^{2}/h$（非平凡相）和$4{e}^{2}/h$ plateaux（平凡相）的序列，这些序列落在非零范围内样本宽度变大时陈数（2D限制）。这些特征是QSH效应和TSC的拓扑性质的表现。
We investigate transport through a normal-superconductor (NS) junction made from a quantum spin Hall (QSH) system with helical edge states and a two-dimensional (2D) chiral topological superconductor (TSC) having a chiral Majorana edge mode. We employ a two-dimensional extended four-band model for HgTe-based quantum wells in a magnetic (Zeeman) field and subject to $s$-wave superconductivity. We show using the Bogoliubov-de Gennes scattering formalism that this structure provides a striking transport signal of a 2D TSC. As a function of the sample width (or Fermi energy) the conductance resonances go through a sequence of $2{e}^{2}/h$ (nontrivial phase) and $4{e}^{2}/h$ plateaux (trivial phase) which fall within the region of a nonzero Chern number (2D limit) as the sample width becomes large. These signatures are a manifestation of the topological nature of the QSH effect and the TSC.