μSR measurements on Sr2RuO4 under 〈110〉 uniaxial stress

Abstract

Muon spin rotation/relaxation ($\ensuremath{\mu}\mathrm{SR}$) and polar Kerr effect measurements provide evidence for a time-reversal symmetry breaking (TRSB) superconducting state in ${\mathrm{Sr}}_{2}{\mathrm{RuO}}_{4}$. However, the absence of a cusp in the superconducting transition temperature (${T}_{\mathrm{c}}$) vs stress and the absence of a resolvable specific heat anomaly at TRSB transition temperature (${T}_{\mathrm{TRSB}}$) under uniaxial stress challenge a hypothesis of TRSB superconductivity. Recent $\ensuremath{\mu}\mathrm{SR}$ studies under pressure and with disorder indicate that the splitting between ${T}_{\mathrm{c}}$ and ${T}_{\mathrm{TRSB}}$ occurs only when the structural tetragonal symmetry is broken. To further test such behavior, we measured ${T}_{\text{c}}$ through susceptibility measurements and ${T}_{\text{TRSB}}$ through $\ensuremath{\mu}\mathrm{SR}$, under uniaxial stress applied along a $\ensuremath{\langle}110\ensuremath{\rangle}$ lattice direction. We have obtained preliminary evidence for suppression of ${T}_{\text{TRSB}}$ below ${T}_{\text{c}}$, at a rate much higher than the suppression rate of ${T}_{\text{c}}$.