Superconductivity in Topological Insulator Sb2Te3 Induced by Pressure

TL;DR

This paper reports the discovery of pressure-induced superconductivity in the topological insulator Sb2Te3, revealing a link between its topological surface states and superconducting properties at ambient and high pressures.

Contribution

It demonstrates that Sb2Te3 becomes superconducting under pressure while retaining its topological surface states, highlighting a new route to topological superconductivity.

Findings

Superconductivity appears in Sb2Te3 at low pressures in the ambient phase.

Carrier type changes from p-type to n-type with increasing pressure.

Sb2Te3 retains Dirac surface states within the ambient phase where superconductivity occurs.

Abstract

Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. Superconductivity was previously realized in a Cu-intercalated Bi2Se3 topological compound or a Bi2Te3 topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb2Te3 when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb2Te3 retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.