Strain-induced time reversal breaking and half quantum vortices near a putative superconducting tetracritical point in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Sr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>RuO</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>

Abstract

Motivated by continuing debate concerning the pairing symmetries of Sr${}_{2}$RuO${}_{4}$, the authors develop a general description of a situation in which superconducting orders are nearly degenerate. They suggest that many seemingly contradictory experimental findings can be reconciled if one assumes this material is near a tetracritical point, where small variations in strain can lead to rich phenomenology. More specifically, the authors characterize possible superconducting domain walls, allowing for spontaneous time-reversal symmetry breaking and the stabilization of half-quantum vortices.

Topics & Concepts