Pressure-induced superconductivity in topological insulator Ge2Bi2Te5 and the evolution with Mn doping

TL;DR

This study demonstrates that applying pressure induces superconductivity in topological insulator Ge2Bi2Te5, with Mn doping affecting the magnetic and superconducting properties, revealing a complex interplay among topology, magnetism, and superconductivity.

Contribution

It provides the first high-pressure transport analysis of Ge2Bi2Te5 and its Mn-doped variants, highlighting the competition between magnetism and superconductivity in topological insulators.

Findings

Pressure induces superconductivity with Tc up to 7.6 K.

Mn doping introduces antiferromagnetic order and suppresses pressure-induced superconductivity.

The phase diagram shows a dome-shaped superconducting region.

Abstract

Introducing superconductivity (SC) or magnetism into topological insulators (TIs) can give rise to novel quantum states and exotic physical phenomena. Here, we report a high-pressure transport study on the TI Ge2Bi2Te5 and its Mn-doped counterparts. The application of pressure induces a SC in Ge2Bi2Te5, which shows a dome-shape phase diagram with the maximum Tc of 7.6 K at 23 GPa. Doping Mn into Ge2Bi2Te5 introduces an antiferromagnetic order at ambient pressure and strongly weakens the pressure-induced SC, demonstrating that magnetism and SC compete in this material system. Present study provides a new platform for investigating the interplay among band topology, magnetism, and SC.