Zhang Rui-Xing, Das Sarma S
Condensed Matter Theory Center and Joint Quantum Institute, Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA.
Phys Rev Lett. 2021 Apr 2;126(13):137001. doi: 10.1103/PhysRevLett.126.137001.
We establish quasi-two-dimensional thin films of iron-based superconductors (FeSCs) as a new high-temperature platform for hosting intrinsic time-reversal-invariant helical topological superconductivity (TSC). Based on the combination of Dirac surface state and bulk extended s-wave pairing, our theory should be directly applicable to a large class of experimentally established FeSCs, opening a new TSC paradigm. In particular, an applied electric field serves as a "topological switch" for helical Majorana edge modes in FeSC thin films, allowing for an experimentally feasible design of gate-controlled helical Majorana circuits. Applying an in-plane magnetic field drives the helical TSC phase into a higher-order TSC carrying corner-localized Majorana zero modes. Our proposal should enable the experimental realization of helical Majorana fermions.
我们将铁基超导体（FeSCs）的准二维薄膜构建为一个承载本征时间反演不变螺旋拓扑超导性（TSC）的新型高温平台。基于狄拉克表面态与体扩展s波配对的结合，我们的理论应可直接应用于一大类已通过实验确立的FeSCs，开启一种新的TSC范式。特别地，施加的电场充当FeSC薄膜中螺旋马约拉纳边缘模式的“拓扑开关”，从而实现一种在实验上可行的栅极控制螺旋马约拉纳电路设计。施加面内磁场会将螺旋TSC相驱动到携带角局域马约拉纳零模的高阶TSC中。我们的提议应能实现螺旋马约拉纳费米子的实验实现。
