In-plane magnetic field phase diagram of superconducting Sr2RuO4

TL;DR

This paper develops a Ginzburg-Landau theoretical framework to analyze the upper critical field anisotropy and phase transitions in the in-plane magnetic field phase diagram of multiband Sr2RuO4, revealing effects of multiband superconductivity.

Contribution

It extends the Ginzburg-Landau theory to multiband superconductors, showing how anisotropy and phase transition features are modified in Sr2RuO4.

Findings

Upper critical field anisotropy can be reduced in multiband superconductors.

Phase transition splitting persists in the multiband case.

Theoretical results are applied to Sr2RuO4.

Abstract

We develop the Ginzburg - Landau theory of the upper critical field in the basal plane of a tetragonal multiband metal in two-component superconducting state. It is shown that typical for the two component superconducting state the upper critical field basal plane anisotropy and the phase transition splitting still exist in a multiband case. However, the value of anisotropy can be effectively smaller than in the single band case. The results are discussed in the application to the superconducting Sr2RuO4.