Higher-Tc Superconducting Phase in Sr2RuO4 Induced by In-Plane Uniaxial Pressure

TL;DR

Applying in-plane uniaxial pressure to Sr2RuO4 enhances its superconducting transition temperature to 3.3 K by inducing a new superconducting phase with a one-component order parameter, depending on pressure direction.

Contribution

This study demonstrates that in-plane uniaxial pressure can induce a higher-Tc superconducting phase in Sr2RuO4, revealing the importance of crystal symmetry and pressure direction in superconductivity.

Findings

Tc increases to 3.3 K under uniaxial pressure

Pressure along [100] direction is more effective

Higher-Tc phase linked to Fermi surface changes

Abstract

We revealed that the superconducting transition temperature Tc of the multi-component superconductor Sr2RuO4 is enhanced to 3.3 K under in-plane uniaxial pressure that reduces the tetragonal crystal symmetry. This result suggests that new superconducting phases with a one-component order parameter are induced. We have also clarified the inplane pressure direction dependence of the emergence of this higher-Tc superconducting phase: pressure along the [100] direction is more favorable than pressure along the [110] direction. This result is probably closely related to the direct shortening of the in-plane Ru-O bond length along the pressure direction and the approach of the gamma Fermi surface to the van Hove singularity under the pressure parallel to the [100] direction.