论文标题
基于铁的超导体中的脱位Majorana绑定状态
Dislocation Majorana Bound States in Iron-based Superconductors
论文作者
论文摘要
我们表明，在没有任何外部磁场的情况下，基于拓扑铁的超导体（例如fete $ _ {1-x} $ se $ _x $）的晶格脱位将本质上捕获非阿布莱利亚主要的准粒子。我们的理论是由近期正常状态拓扑和表面磁性的实验性观察激励的，这些观察结果与Fete $ _ {1-x} $ se $ _x $共存的超导性共存，这种组合自然地唤起了螺丝或边缘旋转两种二维子系统的紧急二级拓扑超导性。这体现了D类新嵌入的高阶拓扑阶段，其中Majorana零模式出现在低维嵌入式子系统的“角落”周围，而不是完整晶体的嵌入式子系统。开发了嵌套域壁理论，以了解这些缺陷Majora零模式的起源。当缺乏表面磁性时，我们进一步发现$ s _ {\ pm} $配对对称性本身能够诱导不同类型的类别DIIII类型的嵌入式高阶拓扑，并具有缺陷型的Majorana Kramers对。我们还提供有关我们建议的现实世界候选物质的详细讨论，包括fete $ _ {1-x} $ se $ _x $，lifeas，$β$ -pdbi $ _2 $以及Bismuth的异质结构，等等。我们的作品，我们的工作确立了lattice缺陷，以实现高度机密量的拓扑范围来源。
We show that lattice dislocations of topological iron-based superconductors such as FeTe$_{1-x}$Se$_x$ will intrinsically trap non-Abelian Majorana quasiparticles, in the absence of any external magnetic field. Our theory is motivated by the recent experimental observations of normal-state topology and surface magnetism that coexist with superconductivity in FeTe$_{1-x}$Se$_x$, the combination of which naturally evokes an emergent second-order topological superconductivity in a two-dimensional subsystem spanned by screw or edge dislocations. This exemplifies a new embedded higher-order topological phase in class D, where Majorana zero modes appear around the "corners" of a low-dimensional embedded subsystem, instead of those of the full crystal. A nested domain wall theory is developed to understand the origin of these defect Majorana zero modes. When the surface magnetism is absent, we further find that $s_{\pm}$ pairing symmetry itself is capable of inducing a different type of class-DIII embedded higher-order topology with defect-bound Majorana Kramers pairs. We also provide detailed discussions on the real-world material candidates for our proposals, including FeTe$_{1-x}$Se$_x$, LiFeAs, $β$-PdBi$_2$, and heterostructures of bismuth, etc. Our work establishes lattice defects as a new venue to achieve high-temperature topological quantum information processing.
