Wu Ya-Jie, Tu Wei, Li Ning
School of Sciences, Xi'an Technological University, Xi'an 710032, People's Republic of China.
J Phys Condens Matter. 2022 Jul 15;34(37). doi: 10.1088/1361-648X/ac7f19.
Higher-order topological superconductors and superfluids (SFs) host lower-dimensional Majorana corner and hinge states since novel topology exhibitions on boundaries. While such topological nontrivial phases have been explored extensively, more possible schemes are necessary for engineering Majorana states. In this paper we propose Majorana corner states could be realized in a two-dimensional attractive quantum spin-Hall insulator with opposite in-plane Zeeman energy at two sublattice sites. The appropriate Zeeman field leads to the opposite Dirac mass for adjacent edges of a square sample, and naturally induce Majorana corner states. This topological phase can be characterized by Majorana edge polarizations, and it is robust against perturbations on random potentials and random phase fluctuations as long as the edge gap remains open. Our work provides a new possibility to realize a second-order topological SF in two dimensions and engineer Majorana corner states.
高阶拓扑超导体和超流体（SFs）由于边界上出现的新奇拓扑结构而拥有低维马约拉纳角态和棱态。虽然这类拓扑非平凡相已得到广泛研究，但还需要更多可行方案来设计马约拉纳态。在本文中，我们提出在一个二维吸引性量子自旋霍尔绝缘体中，当两个子晶格位点具有相反的面内塞曼能时，可以实现马约拉纳角态。合适的塞曼场会导致方形样品相邻边缘的狄拉克质量相反，并自然地诱导出马约拉纳角态。这个拓扑相可以由马约拉纳边缘极化来表征，并且只要边缘能隙保持打开，它对随机势和随机相位涨落的微扰就是稳健的。我们的工作为在二维中实现二阶拓扑超流体以及设计马约拉纳角态提供了一种新的可能性。
