# Observation of topological transition in high-T$_{c}$ superconductor FeTe$_{1-x}$Se$_{x}$/SrTiO$_{3}$(001) monolayers

## TL;DR

This study directly observes a topological transition in high-temperature superconductor monolayers, revealing edge states and providing a promising platform for high-temperature Majorana state realization.

## Contribution

It demonstrates the topological transition in FeTe$_{1-x}$Se$_{x}$/SrTiO$_{3}$ monolayers using ARPES and STM, offering a tunable high-temperature platform for Majorana states.

## Key findings

- Observation of topological transition near the Fermi level.
- Detection of edge states via scanning tunneling spectroscopy.
- Theoretical calculations support experimental results.

## Abstract

Superconductors with topological surface or edge states have been intensively explored for the prospect of realizing Majorana bound states, which obey non-Abelian statistics and are crucial for topological quantum computation. The traditional routes for making topological insulator/superconductor and semiconductor/superconductor heterostructures suffer fabrication difficulties and can only work at low temperature. Here, we use angle-resolved photoemission spectroscopy to directly observe the evolution of a topological transition of band structure nearby the Fermi level in two-dimensional high-T$_{c}$ superconductor FeTe$_{1-x}$Se$_{x}$/SrTiO$_{3}$(001) monolayers, fully consistent with our theoretical calculations. Furthermore, evidence of edge states is revealed by scanning tunneling spectroscopy with assistance of theoretical calculations. Our study provides a simple and tunable platform for realizing and manipulating Majorana states at high temperature.

---
Source: https://tomesphere.com/paper/1903.05968