Corner states, hinge states and Majorana modes in SnTe nanowires

TL;DR

This paper explores the topological states in SnTe nanowires, revealing the origin of corner and hinge states, and demonstrating how Majorana modes emerge and can be manipulated with symmetry-breaking fields and superconductivity.

Contribution

It provides a detailed analysis of symmetry-protected topological states in SnTe nanowires, including the emergence of Majorana modes under various conditions, which is a novel insight.

Findings

Robust corner and hinge states in the normal state.

Inversion-symmetry-protected gapless bulk Majorana modes with quantized thermal conductance.

Localized Majorana zero modes at wire ends when symmetry is broken.

Abstract

SnTe materials are one of the most flexible material platforms for exploring the interplay of topology and different types of symmetry breaking. We study symmetry-protected topological states in SnTe nanowires in the presence of various combinations of Zeeman field, s-wave superconductivity and inversion-symmetry-breaking field. We uncover the origin of robust corner states and hinge states in the normal state. In the presence of superconductivity, we find inversion-symmetry-protected gapless bulk Majorana modes, which give rise to quantized thermal conductance in ballistic wires. By introducing an inversion-symmetry-breaking field, the bulk Majorana modes become gapped and topologically protected localized Majorana zero modes appear at the ends of the wire.