Surface electronic state of superconducting topological crystalline insulator

TL;DR

This paper investigates the surface electronic states of a doped topological crystalline insulator in the superconducting phase, revealing mirror-protected zero-energy states and their doping dependence, which could impact topological superconductor research.

Contribution

It provides a theoretical analysis of surface Andreev bound states in a superconducting topological crystalline insulator, highlighting mirror symmetry protection and doping effects.

Findings

Mirror-protected zero-energy Andreev bound states at the (001) surface

Surface Andreev bound states shift with doping levels

Presence of Dirac surface states influences superconducting surface states

Abstract

We study the surface state of a doped topological crystalline insulator in the superconducting state. Motivated by Sn$_{1-x}$In$_x$Te, we consider fully gapped pair potentials and calculate the surface spectral function. It is found that mirror-protected zero-energy Andreev bound states appear at the (001) surface and that these states can move along the mirror symmetric line on the surface Brillouin zone. We also show that the surface Andreev bound state changes systematically with doping due to the presence of the Dirac surface state in the normal state.