In-plane magnetic penetration depth in Sr${}_2$RuO${}_4$: muon-spin rotation/relaxation study

Abstract

We report on measurements of the in-plane magnetic penetration depth (${\lambda }_{\mathrm{ab}}$) in single crystals of Sr${}_2$RuO${}_4$ down to $\simeq 0.015$ K by means of muon-spin rotation/relaxation. The linear temperature dependence of ${\lambda }_{\mathrm{ab}}^{-2}$ for $T\lesssim 0.7$ K suggests the presence of nodes in the superconducting gap. This statement is further substantiated by observation of the Volovik effect, $i.e.$ the reduction of ${\lambda }_{ab}^{-2}$ as a function of the applied magnetic field. The experimental zero-field and zero-temperature value of ${\lambda }_{\mathrm{ab}}=124(3)$ nm agrees with ${\lambda }_{\mathrm{ab}}\simeq 130$ nm, calculated based on results of electronic structure measurements reported in [Phys. Rev X 9, 021048 (2019)]. Our analysis reveals that a simple nodal superconducting energy gap, described by the lowest possible harmonic of a gap function, does not capture the dependence of ${\lambda }_{\mathrm{ab}}^{-2}$ on $T$, so the higher angular harmonics of the energy gap function need to be introduced.

7 pages, 3 figures

References in corpus (8)

• Evidence for complex order parameter in La_{1.83}Sr_{0.17}CuO_4
• Momentum-resolved superconducting gap in the bulk of Ba${}_{1-x}$K${}_x$Fe${}_2$As${}_2$ from combined ARPES and $\mu$SR measurements
• Comparison of different methods for analyzing $\mu$SR line shapes in the vortex state of type-II superconductors
• Nodeless spin triplet superconducting gap in Sr2RuO4
• Muon-spin rotation measurements of the vortex state in Sr${}_2$RuO${}_4$: type-1.5 superconductivity, vortex clustering and a crossover from a triangular to a square vortex lattice
• Higher angular momentum pairings in interorbital shadowed-triplet superconductors: Application to Sr${}_2$RuO${}_4$
• Hierarchy of Lifshitz transitions in the surface electronic structure of Sr${}_2$RuO${}_4$ under uniaxial compression
• Higher angular momentum pairing states in Sr${}_2$RuO${}_4$ in the presence of longer-range interactions

Cited by in corpus (4)

• Orientation-dependent Josephson effect in spin-singlet superconductor/altermagnet/spin-triplet superconductor junctions
• Muon Knight shift as a precise probe of the superconducting symmetry of Sr${}_2$RuO${}_4$
• Josephson effects in the spin-triplet superconductor/altermagnet/spin-triplet superconductor junctions: the detection of the intrinsic $\mathbf{d}$-vector
• Beyond Homes scaling: disorder, the Planckian bound and a new universality