Exotic Cooper pairing in multi-orbital models of Sr${}_2$RuO${}_4$

Abstract

The unconventional superconductivity in Sr${}_2$RuO${}_4$ continues to defy a unified interpretation. In this paper, we focus on some novel aspects of its superconducting pairing by exploiting the orbital degree of freedom in this material. The multi-orbital nature, combined with the symmetry of the orbitals involved, leads to a plethora of exotic Cooper pairings not accessible in single-orbital systems. Essential physics is illustrated first using a two-orbital model with $d_{xz}$- and $d_{yz}$-orbitals. We classify the gap functions according to the underlying lattice symmetries, analyze the effective theories of a few representative pairings, and make connections to Sr${}_2$RuO${}_4$ in the course. In particular, we show how spin-orbit coupling may entangle spin-triplet and spin-singlet pairings. For completeness, the classification is generalized to the three-orbital model involving the $d_{xy}$-orbital as well. The orbital-basis approach distinguishes from the itinerant-band description for Sr${}_2$RuO${}_4$, and hence offers an alternative perspective to investigate its enigmatic superconducting state.

arXiv comment7 pages, 1 figure and 2 tables. Published version

References in corpus (49)

• 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
• Evaluation of Spin-Triplet Superconductivity in Sr2RuO4
• Pronounced drop of ${}^{17}$O NMR Knight shift in superconducting state of Sr${}_2$RuO${}_4$
• Chiral Superconductors
• Strong Peak in $T_c$ of Sr${}_2$RuO${}_4$ Under Uniaxial Pressure
• Chiral P-Wave Order in Sr_2RuO_4
• Fermi Surface, Surface States, and Surface Reconstruction in Sr2RuO4
• A polarized neutron-scattering study of the Cooper-pair moment in Sr2RuO4
• Upper limit on spontaneous supercurrents in Sr${}_2$RuO${}_4$
• Detailed Topography of the Fermi Surface of Sr2RuO4
• Hidden quasi one-dimensional superconductivity in Sr${}_2$RuO${}_4$
• Interband proximity effect and nodes of superconducting gap in Sr2RuO4
• Limits on Superconductivity-Related Magnetization in Sr${}_2$RuO${}_4$ and PrOs${}_4$Sb${}_{12}$ from Scanning SQUID Microscopy
• Spontaneous Hall effect in chiral p-wave superconductor
• Multi-flavor bosonic Hubbard models in the first excited Bloch band of an optical lattice
• Spin triplet superconductivity with line nodes in Sr2RuO4
• Even Parity, Orbital Singlet and Spin Triplet Pairing for Superconducting $La(O_{1-x}{F}_x)FeAs$
• Interlayer Coupling and p-wave Pairing in Strontium Ruthenate
• Is Sr2RuO4 a Chiral P-Wave Superconductor?
• Pairing symmetry and dominant band in Sr2RuO4
• Theory of superconductivity in a three-orbital model of Sr${}_2$RuO${}_4$
• Identifying detrimental effects for multi-orbital superconductivity - Application to Sr${}_2$RuO${}_4$
• Vertical line nodes in the superconducting gap structure of Sr2RuO4
• Roles of Electron Correlations in the Spin-Triplet Superconductivity of Sr2RuO4
• Intrinsic Hall effect in a multiband chiral superconductor in the absence of an external magnetic field
• Superconducting Double Transition and the Upper Critical Field Limit of Sr2RuO4 in Parallel Magnetic Fields
• Vanishing edge currents in non-$p$-wave topological chiral superconductors
• Hund interaction, spin-orbit coupling and the mechanism of superconductivity in strongly hole-doped iron pnictides
• Superconducting order parameter of Sr${}_2$RuO${}_4$: a microscopic perspective
• Identifying spin-triplet pairing in spin-orbit coupled multi-band superconductors
• Odd-frequency superconductivity in Sr${}_2$RuO${}_4$ measured by Kerr rotation
• Spin Triplet Superconductivity in Sr2RuO4 due to Orbital and Spin Fluctuations: Analysis by Two-Dimensional Renormalization Group Theory
• Spin-triplet superconductivity in Sr2RuO4 due to orbital and spin fluctuations: Analyses by two-dimensional renormalization group theory and self-consistent vertex-correction method
• Micron-scale measurements of low anisotropic strain response of local $T_c$ in Sr${}_2$RuO${}_4$
• Intrinsic optical dichroism in the chiral superconducting state of Sr${}_2$RuO${}_4$
• Theory of chiral $p$-wave superconductivity with near-nodes for Sr${}_2$RuO${}_4$
• Pairing symmetry and properties of iron-based high temperature superconductors
• Specific-heat evidence of the first-order superconducting transition in Sr2RuO4
• Charge and spin collective modes in a quasi-1D model of Sr2RuO4
• Possible three-dimensional nematic odd-parity superconductivity in Sr${}_2$RuO${}_4$
• Spin Density Wave Fluctuations and p-wave Pairing in Sr2RuO4
• Symmetry of superconducting states with two orbitals on a tetragonal lattice: application to $La{O}_{1-x}{F}_{x}FeAs$
• Superconducting pairing in Sr${}_2$RuO${}_4$ from weak to intermediate coupling
• Intrinsic ac anomalous Hall effect of nonsymmorphic chiral superconductors with an application to $\mathrm{UP}{\mathrm{t}}_3$
• Leggett modes and multi-band superconductivity in Sr2RuO4
• Hund's coupling stabilized superconductivity in the presence of spin-orbit interactions
• Simultaneous Evidence for Pauli Paramagnetic Effects and Multiband Superconductivity in KFe${}_2$As${}_2$ by Small-Angle Neutron Scattering Studies of the Vortex Lattice
• Anisotropy and multiband superconductivity in Sr2RuO4

Cited by in corpus (28)

• Recent progress on superconductors with time-reversal symmetry breaking
• Inhomogeneous time-reversal symmetry breaking in ${\mathrm{Sr}}_2\mathrm{Ru}{\mathrm{O}}_4$
• Superconducting state of Sr${}_2$RuO${}_4$ in the presence of longer-range Coulomb interactions
• Quantitative Theory of Triplet Pairing in the Unconventional Superconductor LaNiGa${}_2$
• 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
• Shadowed triplet pairings in Hund's metals with spin-orbit coupling
• Multiorbital singlet pairing and $d+d$ superconductivity
• Superconductivity in Correlated Multi-Orbital Systems with Spin-Orbit Coupling: Coexistence of Even- and Odd-Frequency Pairing and the Case of Strontium Ruthenate
• Distinct reduction of Knight shift in superconducting state of Sr${}_2$RuO${}_4$ under uniaxial strain
• 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
• Superconductivity in multiorbital systems with repulsive interactions: Hund's pairing vs. spin-fluctuation pairing
• Hidden anomalous Hall effect in Sr${}_2$RuO${}_4$ with chiral superconductivity dominated by the Ru $d_{xy}$ orbital
• Multipole-fluctuation pairing mechanism of $d_{x^2-y^2}+ig$ superconductivity in Sr${}_2$RuO${}_4$
• Magnetically-textured superconductivity in elemental Rhenium
• Exotic interband pairing in multiband superconductors
• Inter-orbital p- and d-wave pairings between $d_{xz/yz}$ and $d_{xy}$ orbitals in Sr${}_2$RuO${}_4$
• Possibility of mixed helical p-wave pairings in Sr${}_2$RuO${}_4$
• Quantum-geometry-induced anomalous Hall effect in nonunitary superconductors and application to Sr${}_2$RuO${}_4$
• Degeneracy between even- and odd-parity superconductivity in the quasi-1D Hubbard model and implications for Sr2RuO4
• A review of some new perspectives on the theory of superconducting Sr${}_2$RuO${}_4$
• Possible two-component spin-singlet pairings in Sr2RuO4
• Spin-orbit-coupled superconductivity with spin-singlet non-unitary pairing
• Reconciling $\pi$ phase shift in Josephson junction experiments with even-parity superconductivity in Sr${}_2$RuO${}_4$
• Enhanced Spin-Orbit Coupling in a Correlated Metal
• Evolution of Interorbital Superconductor to Intraorbital Spin-Density Wave in Layered Ruthenates
• Quantum-geometry-induced intrinsic optical anomaly in multiorbital superconductors