Majorana Zero Modes in a Heterogenous Structure of Topological and Trivial Domains in FeSe$_{1-x}$Te$_x$

TL;DR

This paper explains the presence of Majorana zero modes in FeSe$_{1-x}$Te$_x$ through a heterogeneous mixture of topological and trivial superconducting domains, identifying spectroscopic signatures and domain wall Majorana modes.

Contribution

It introduces a model of heterogeneous domains to explain MZMs in FeSe$_{1-x}$Te$_x$, including spectroscopic signatures and dynamic transfer of Majorana modes.

Findings

Vortices in topological domains host MZMs.

Spectroscopic signatures distinguish topological from trivial vortices.

Majorana modes transfer across domain walls when vortices move.

Abstract

We propose that the existence of vortices in FeSe$_{1-x}$Te$_x$ with and without Majoarana zero modes (MZMs) can be explained by a heterogeneous mixture of strong topological and trivial superconducting domains, with only vortices in the former exhibiting MZMs. We identify the spectroscopic signatures of topological and trivial vortices and show that they are necessarily separated by a domain wall harboring Majorana edge modes. We demonstrate that when a vortex is moved from a trivial to a topological domain in real time, a domain wall Majorana edge mode is transferred to the vortex as an MZM.