Searching for gap zeros in Sr2RuO4 via field-angle-dependent specific-heat measurement

Abstract

The gap structure of Sr${}_2$RuO${}_4$, which is a longstanding candidate for a chiral p-wave superconductor, has been investigated from the perspective of the dependence of its specific heat on magnetic field angles at temperatures as low as 0.06 K ($\sim 0.04T_{\mathrm{c}}$). Except near $H_{c2}$, its fourfold specific-heat oscillation under an in-plane rotating magnetic field is unlikely to change its sign down to the lowest temperature of 0.06 K. This feature is qualitatively different from nodal quasiparticle excitations of a quasi-two-dimensional superconductor possessing vertical lines of gap minima. The overall specific-heat behavior of Sr${}_2$RuO${}_4$ can be explained by Doppler-shifted quasiparticles around horizontal line nodes on the Fermi surface, whose in-plane Fermi velocity is highly anisotropic, along with the occurrence of the Pauli-paramagnetic effect. These findings, in particular, the presence of horizontal line nodes in the gap, call for a reconsideration of the order parameter of Sr${}_2$RuO${}_4$.

5 pages, 3 figures (main text) + 3 pages, 3 figures (supplemental material), accepted for publication in J. Phys. Soc. Jpn

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Cited by in corpus (44)

• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• 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${}_4$
• A proposal for reconciling diverse experiments on the superconducting state in Sr2RuO4
• Stabilizing Even-Parity Chiral Superconductivity in Sr${}_2$RuO${}_4$
• Direct Observation of a Uniaxial Stress-driven Lifshitz Transition in Sr${}_2$RuO${}_4$
• Evidence for even parity unconventional superconductivity in Sr${}_2$RuO${}_4$
• Superconducting order parameter of Sr${}_2$RuO${}_4$: a microscopic perspective
• Reduction of the spin susceptibility in the superconducting state of Sr2RuO4 observed by polarized neutron scattering
• 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
• Improved Single-Crystal Growth of Sr${}_2$RuO${}_4$
• Theory of Strain-Induced Magnetic Order and Splitting of $T_c$ and $T_{\mathrm{TRSB}}$ in Sr${}_2$RuO${}_4$
• Group-theoretic classification of superconducting states of Strontium Ruthenate
• Symmetry-based approach to nodal structures: Unification of compatibility relations and gapless point classifications
• Heat capacity double transitions in time-reversal symmetry broken superconductors
• Normal state ${}^{17}$O NMR studies of Sr${}_2$RuO${}_4$ under uniaxial stress
• Inter-orbital singlet pairing in Sr${}_2$RuO${}_4$: a Hund's superconductor
• Horizontal Line Nodes in Sr2RuO4 Proved by Spin Resonance
• Spin gap and L modulated intensity at the low-energy incommensurate magnetic fluctuations in the superconducting state of Sr2RuO4
• Constraints on the superconducting state of Sr${}_2$RuO${}_4$ from elastocaloric measurements
• Anomalous Enhancement of Upper Critical Field in Sr2RuO4 Thin Films
• Identifying possible pairing states in Sr${}_2$RuO${}_4$ by tunneling spectroscopy
• Modulation vector of the Fulde-Ferrell-Larkin-Ovchinnikov state in CeCoIn5 revealed by high-resolution magnetostriction measurements
• Multipole-fluctuation pairing mechanism of $d_{x^2-y^2}+ig$ superconductivity in Sr${}_2$RuO${}_4$
• Effects of deep superconducting gap minima and disorder on residual thermal transport in $\mathrm{S}{\mathrm{r}}_2\mathrm{Ru}{\mathrm{O}}_4$
• Impurity induced double transitions for accidentally degenerate unconventional pairing states
• Characterization of Sr2RuO4 Josephson junctions made of epitaxial films
• Effects of orbital selective dynamical correlation on the spin susceptibility and superconducting symmetries in Sr${}_2$RuO${}_4$
• Possible two-component spin-singlet pairings in Sr2RuO4
• Microscopic Eilenberger theory of Fulde-Ferrell-Larkin-Ovchinnikov states in the presence of vortices
• Theoretical studies for identifying horizontal line nodes via angle-resolved density of states measurements ---Application to Sr${}_2$RuO${}_4$---
• Impurity effect on Bogoliubov Fermi surfaces: Analysis based on iron-based superconductors
• Evening out the spin and charge parity to increase T${}_c$ in unconventional superconductor Sr_{2}RuO_{4}
• High-pressure synthesis of Ba${}_2$RhO${}_4$, a rhodate analogue of the layered perovskite Sr-ruthenate
• Fulde-Ferrell-Larkin-Ovchinnikov State in Perpendicular Magnetic Fields in Strongly Pauli-Limited Quasi-Two-Dimensional Superconductors
• Vestigial Van Hove singularity and higher-temperature superconducting phase induced by perpendicular uniaxial pressures in quasi-two-dimensional superconductors
• Muon Knight shift as a precise probe of the superconducting symmetry of Sr${}_2$RuO${}_4$
• Distinguishing $d_{xz}+i{d}_{yz}$ and $d_{x^2-y^2}$ pairing in $S{r}_{2}Ru{O}_4$ by high magnetic field H-T phase diagrams
• Stability of Mixed-Symmetry Superconducting States with Broken Time-Reversal Symmetry against Lattice Distortions
• Nodal Superconductivity of UTe${}_2$ Probed by Field-Angle-Resolved Specific Heat on a Crystal with $T_{\mathrm{c}}=2.1$ K
• Evolution and Instability of Bogoliubov Fermi Surfaces under Zeeman Field
• A Chiral Triplet Quasi-Two-Dimensional Superconductor in a Parallel Magnetic Field
• High-resolution magnetostriction measurements of the Pauli-limited superconductor Sr2RuO4