Quantum critical point and superconducting dome in the pressure phase diagram of o-TaS3

TL;DR

This study investigates how applying pressure to o-TaS3 affects its electronic phases, revealing a quantum critical point and a superconducting dome, which suggest a universal mechanism linking quantum fluctuations and superconductivity.

Contribution

It provides the first detailed experimental evidence of a quantum critical point and superconducting dome in o-TaS3 under high pressure, highlighting their relationship.

Findings

Quantum critical point at 11.5 GPa

Superconducting dome with Tc up to 3.1K

Charge density wave transition suppressed by pressure

Abstract

We measure the electrical resistance of o-TaS3 between 1K and 300K under pressures up to 20GPa. We observe a gradual decrease of the charge density wave transition temperature with increasing pressure P following a mean-field quantum fluctuation power law with a quantum critical point at a pressure Pc = 11.5GPa. Around the quantum critical point we observe a superconducting dome with a maximum superconducting transition temperature Tc = 3.1K. Such dome is similar to superconducting domes around other types of order suggesting that the QCP is directly responsible for the enhancement of superconductivity through a universal mechanism still not well understood.