Pressure induced Superconductor-Insulator transition in the spinel compound CuRh2S4

TL;DR

This study investigates how applying pressure to CuRh2S4 causes a transition from superconducting to insulating behavior, revealing a critical pressure where superconductivity abruptly ceases and insulation emerges.

Contribution

First experimental observation of a pressure-induced superconductor-insulator transition in CuRh2S4, mapping the critical pressure range and behavior of Tc under pressure.

Findings

Superconducting transition temperature increases with pressure up to 4.0 GPa.

Superconductivity abruptly disappears between 5.0 and 5.6 GPa.

CuRh2S4 becomes an insulator beyond the critical pressure.

Abstract

We performed resistivity measurements in CuRh$_{2}$S$_{4}$ under quasi-hydrostatic pressure of up to 8.0 GPa, and found a pressure induced superconductor-insulator (SI) transition. Initially, with increasing pressure, the superconducting transition temperature $T_c$ increases from 4.7 K at ambient pressure to 6.4 K at 4.0 GPa, but decreases at higher pressures. With further compression, superconductivity in CuRh$_{2}$S$_{4}$ disappears abruptly at a critical pressure $P_{\rm SI}$ between 5.0 and 5.6 GPa, when it becomes an insulator.