Strong Increase in Ultrasound Attenuation Below T${}_{\mathrm{c}}$ in Sr${}_2$RuO${}_4$: Possible Evidence for Domains

Abstract

Recent experiments suggest that the superconducting order parameter of Sr${}_2$RuO${}_4$ has two components. A two-component order parameter has multiple degrees of freedom in the superconducting state that can result in low-energy collective modes or the formation of domain walls -- a possibility that would explain a number of experimental observations including the smallness of the time reversal symmetry breaking signal at T${}_{\mathrm{c}}$ and telegraph noise in critical current experiments. We perform ultrasound attenuation measurements across the superconducting transition of Sr${}_2$RuO${}_4$ using resonant ultrasound spectroscopy (RUS). We find that the attenuation for compressional sound increases by a factor of seven immediately below T${}_{\mathrm{c}}$, in sharp contrast with what is found in both conventional ($s$-wave) and high-T${}_{\mathrm{c}}$ ($d$-wave) superconductors. We find our observations to be most consistent with the presence of domain walls between different configurations of the superconducting state. The fact that we observe an increase in sound attenuation for compressional strains, and not for shear strains, suggests an inhomogeneous superconducting state formed of two distinct, accidentally-degenerate superconducting order parameters that are not related to each other by symmetry. Whatever the mechanism, a factor of seven increase in sound attenuation is a singular characteristic with which any potential theory of the superconductivity in Sr${}_2$RuO${}_4$ must be reconciled.

References in corpus (32)

• Time-Reversal Symmetry Breaking Superconductivity in Sr2RuO4
• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• Observation of half-height magnetization steps in Sr2RuO4
• Bounding the pseudogap with a line of phase transitions in YBCO cuprate superconductors
• Split superconducting and time-reversal symmetry-breaking transitions, and magnetic order in Sr${}_2$RuO${}_4$ under uniaxial stress
• Ultrasound Attenuation in Sr${}_2$RuO${}_4$: an Angle-Resolved Study of the Superconducting Gap Function
• Thermodynamic Evidence for a Two-Component Superconducting Order Parameter in Sr${}_2$RuO${}_4$
• Ultrasound evidence for a two-component superconducting order parameter in Sr${}_2$RuO${}_4$
• Stabilizing Even-Parity Chiral Superconductivity in Sr${}_2$RuO${}_4$
• A proposal for reconciling diverse experiments on the superconducting state in Sr2RuO4
• On the Calculation of the Quality Factor in Contemporary Photonic Resonant Structures
• Knight Shift and Leading Superconducting Instability From Spin Fluctuations in Sr2RuO4
• Momentum Resolved Superconducting Energy Gaps of Sr${}_2$RuO${}_4$ from Quasiparticle Interference Imaging
• Vertical line nodes in the superconducting gap structure of Sr2RuO4
• Evidence from Tunneling Spectroscopy for a Quasi-One Dimensional Origin of Superconductivity in Sr2RuO4
• High sensitivity heat capacity measurements on Sr2RuO4 under uniaxial pressure
• Superconducting order parameter of Sr${}_2$RuO${}_4$: a microscopic perspective
• Inhomogeneous time-reversal symmetry breaking in ${\mathrm{Sr}}_2\mathrm{Ru}{\mathrm{O}}_4$
• A key role of correlation effects in the Lifshitz transition in Sr${}_2$RuO${}_4$
• Micron-scale measurements of low anisotropic strain response of local $T_c$ in Sr${}_2$RuO${}_4$
• Superconducting state of Sr${}_2$RuO${}_4$ in the presence of longer-range Coulomb interactions
• Superconducting order of ${\mathrm{Sr}}_2{\mathrm{RuO}}_4$ from a three-dimensional microscopic model
• Avoided Valence Transition in a Plutonium Superconductor
• Improved Single-Crystal Growth of Sr${}_2$RuO${}_4$
• One-Component Order Parameter in URu${}_2$Si${}_2$ Uncovered by Resonant Ultrasound Spectroscopy and Machine Learning
• Charge and spin collective modes in a quasi-1D model of Sr2RuO4
• Ultrasound attenuation in gap-anisotropic systems
• Higher angular momentum pairings in interorbital shadowed-triplet superconductors: Application to Sr${}_2$RuO${}_4$
• Strain-induced time reversal breaking and half quantum vortices near a putative superconducting tetra-critical point in Sr${}_2$RuO${}_4$
• Ultrasonic attenuation in clean d-wave superconductors
• High sensitivity heat capacity measurements on Sr2RuO4 under uniaxial pressure

Cited by in corpus (7)

• Superconductivity in Correlated Multi-Orbital Systems with Spin-Orbit Coupling: Coexistence of Even- and Odd-Frequency Pairing and the Case of Strontium Ruthenate
• Constraints on the superconducting state of Sr${}_2$RuO${}_4$ from elastocaloric measurements
• Higher angular momentum pairing states in Sr${}_2$RuO${}_4$ in the presence of longer-range interactions
• $T_c$ and the elastocaloric effect of Sr${}_2$RuO${}_4$ under $⟨110⟩$ uniaxial stress: no indications of transition splitting
• Ultrasonic investigation of the Kondo semimetal CeBi
• Multipolar Fermi Surface Deformations in Sr${}_2$RuO${}_4$ Probed by Resistivity and Sound Attenuation: A Window into Electron Viscosity and the Collision Operator
• Influence of Fermi Surface Geometry and Van Hove Singularities on the Optical Response of Sr${}_2$RuO${}_4$