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.
@article{arxiv.1501.02868,
title = {Higher-Tc Superconducting Phase in Sr2RuO4 Induced by In-Plane Uniaxial Pressure},
author = {Haruka Taniguchi and Keigo Nishimura and Swee K. Goh and Shingo Yonezawa and Yoshiteru Maeno},
journal= {arXiv preprint arXiv:1501.02868},
year = {2015}
}