Pressure induced Superconductivity in Topological Compound Bi2Te3

TL;DR

Applying pressure to Bi2Te3 induces superconductivity while preserving its topological surface states, potentially enabling the realization of Majorana fermions and topological superconductivity.

Contribution

This study demonstrates pressure-induced superconductivity in Bi2Te3 and confirms the persistence of topological surface states under pressure, suggesting a route to topological superconductivity.

Findings

Superconductivity appears at around 3K under pressure.

Topological surface states remain intact under pressure.

Potential for Majorana fermions on the surface.

Abstract

Bi2Te3 compound has been theoretically predicted (1) to be a topological insulator, and its topologically non-trivial surface state with a single Dirac cone has been observed in photoemission experiments (2). Here we report that superconductivity (Tc^~3K) can be induced in Bi2Te3 as-grown single crystal (with hole-carriers) via pressure. The first-principles calculations show that the electronic structure under pressure remains to be topologically nontrivial, and the Dirac-type surface states can be well distinguished from bulk states at corresponding Fermi level. The proximity effect between superconducting bulk states and Dirac-type surface state could generate Majorana fermions on the surface. We also discuss the possibility that the bulk state could be a topological superconductor.