FLEX analysis of the impact of strain and 3D coupling on the superconducting transition of Sr₂RuO₄

Analysis of the superconducting transition of Sr₂RuO₄ via application of the fluctuation exchange approximation (FLEX) to realistic tight-binding and interaction parameters leads to a d-wave pairing state with p-wave components induced through spin-orbit coupling. While the FLEX-generated superconducting state does not account for time-reversal symmetry breaking signatures observed in μSR and Kerr effect experiments, it is consistent with apparent line-nodes in thermodynamic data as well as the absence of significant observed Knight shifts across T_c on account of spin-orbit coupling rather than a fully-triplet pairing state. We present results for the transition temperature as a function of in-plane strain in the two-dimensional limit and show that, in accordance with experiment, T_c, is supressed rapidly when the Fermi level passes through the van Hove singularity in the γ band with no strain induced splitting of the transition. However, these results do not account for the initial enhancement of T_c as strain is increased from zero. We will also report the impact of 3D coupling on this analysis.