Superconductivity of topological insulator Bi2Se3 at high pressures

TL;DR

This study investigates how applying high pressure induces and affects superconductivity in Bi2Se3, revealing structural transitions and a phase diagram that links pressure, carrier density, and superconducting transition temperature.

Contribution

It provides the first detailed phase diagram of pressure-induced superconductivity and structural evolution in Bi2Se3, highlighting the relationship between pressure, carrier density, and superconductivity.

Findings

Superconductivity emerges around 12 GPa with Tc about 4.4K.

Tc peaks at 8.5K near 16 GPa and then decreases.

Structural transitions occur at 12 GPa, 20 GPa, and above 29 GPa.

Abstract

The pressure induced superconductivity and structural evolution for Bi2Se3 single crystal have been studied. The emergence of superconductivity with onset transition temperature (Tc) about 4.4K is observed around 12GPa. Tc increases rapidly to the highest 8.5K at 16GPa, decreases to 6.5K at 21GPa, then keep almost constant. It is found that Tc versus pressure is closely related to the carrier density which increases by more than two orders of magnitude from 2GPa to 23GPa. High pressure synchrotron radiation measurements reveal structure transitions occur around 12GPa, 20GPa, and above 29GPa, respectively. A phase diagram of superconductivity versus pressure is obtained.