Higher-Tc superconducting phase in Sr2RuO4 induced by uniaxial pressure

TL;DR

Applying a small uniaxial pressure to Sr2RuO4 induces a higher-temperature superconducting phase, revealing two distinct superconducting states and suggesting pressure-induced structural effects enhance superconductivity.

Contribution

This study demonstrates that uniaxial pressure can induce a higher-Tc phase in Sr2RuO4, revealing new superconducting states linked to crystal distortions beyond elastic limits.

Findings

Uniaxial pressure of 0.2 GPa raises Tc above 3 K.

Pure Sr2RuO4 exhibits two superconducting phases.

Higher Tc phase associated with anisotropic crystal distortions.

Abstract

We have investigated uniaxial pressure effect on superconductivity of pure Sr2RuO4, whose intrinsic superconducting transition temperature Tc is 1.5 K. It was revealed that a very low uniaxial pressure along the c axis, only 0.2 GPa, induces superconductivity with the onset Tc above 3 K. The present results indicate that pure Sr2RuO4 has two superconducting phases with Tc = 1.5 K and with varying Tc up to 3.2 K. The latter phase exhibits unusual features and is attributable to anisotropic crystal distortions beyond the elastic limit.