Observation of surface states on heavily indium doped SnTe(111), a superconducting topological crystalline insulator

TL;DR

This study investigates heavily indium-doped SnTe(111), revealing that topological surface states persist despite increased doping and superconductivity, expanding understanding of topological crystalline insulators with higher indium content.

Contribution

It presents the growth, characterization, and ARPES analysis of heavily indium-doped SnTe(111), showing surface states survive at higher doping levels with enhanced superconductivity.

Findings

Surface states persist at high indium doping levels.

Superconducting transition temperature increases nearly fourfold.

Dirac-like surface states are maintained despite strong p-type doping.

Abstract

The topological crystalline insulator tin telluride is known to host superconductivity when doped with indium (Sn$_{1-x}$In$_{x}$Te), and for low indium contents ($x=0.04$) it is known that the topological surface states are preserved. Here we present the growth, characterization and angle resolved photoemission spectroscopy analysis of samples with much heavier In doping (up to $x\approx0.4$), a regime where the superconducting temperature is increased nearly fourfold. We demonstrate that despite strong p-type doping, Dirac-like surface states persist.