Superconductivity at 27 K in tetragonal FeSe under high pressure

TL;DR

This study reports a significant increase in the superconducting transition temperature of tetragonal FeSe under high pressure, reaching 27 K at 1.48 GPa, with implications for applications and understanding superconductivity mechanisms.

Contribution

It demonstrates a high-pressure-induced enhancement of Tc in FeSe and explores its potential for applications and insights into iron-based superconductor mechanisms.

Findings

Tc reached 27 K at 1.48 GPa

High upper critical field (~72 T) estimated

Pressure coefficient of 9.1 K/GPa

Abstract

A huge enhancement of the superconducting transition temperature Tc was observed in tetragonal FeSe superconductor under high pressure. The onset temperature became as high as 27 K at 1.48 GPa and the pressure coefficient showed a huge value of 9.1 K/GPa. The upper critical field Hc2 was estimated to be ~ 72 T at 1.48 GPa. Because of the high Hc2, FeSe system may be a candidate for application as superconducting wire rods. Moreover, the investigation of superconductivity on simple structured FeSe may provide important clues to the mechanism of superconductivity in iron-based superconductors.