• DOI:10.1103/PhysRevB.104.054518
• Corpus ID: 235293799

Strain-induced time reversal breaking and half quantum vortices near a putative superconducting tetra-critical point in Sr$_2$RuO$_4$

@inproceedings{Yuan2021StraininducedTR,
  title={Strain-induced time reversal breaking and half quantum vortices near a putative superconducting tetra-critical point in Sr\$\_2\$RuO\$\_4\$},
  author={Andrew C. Yuan and Erez Berg and Steven A. Kivelson},
  year={2021}
}

• Andrew C. Yuan, E. Berg, S. Kivelson
• Published 2 June 2021
• Physics

It has been shown [1] that many seemingly contradictory experimental findings concerning the superconducting state in Sr2RuO4 can be accounted for as resulting from the existence of an assumed tetra-critical point at near ambient pressure at which dx2−y2 and gxy(x2−y2) superconducting states are degenerate. We perform both a Landau-Ginzburg and a microscopic mean-field analysis of the effect of spatially varying strain on such a state. In the presence of finite xy shear strain, the superconducting state consists of two possible symmetry-related time-reversal symmetry (TRS) preserving states: d± g. However, at domain walls between two such regions, TRS can be broken, resulting in a d+ ig state. More generally, we find that various natural patterns of spatially varying strain induce a rich variety of superconducting textures, including half-quantum fluxoids. These results may resolve some of the apparent inconsistencies between the theoretical proposal and various experimental observations, including the suggestive evidence of half-quantum vortices [2].