Pairing state at an interface of Sr${}_2$RuO${}_4$: parity-mixing, restored time-reversal symmetry, and topological superconductivity

Abstract

We investigate pairing states realized at the (001) interface of a spin-triplet superconductor Sr${}_2$RuO${}_4$ on the basis of microscopic calculations. Because of a Rashba-type spin-orbit interaction induced at the interface, strong parity-mixing of Cooper pairs between a spin-singlet state and a spin-triplet state occurs in this system. There are also strong inter-band pair correlations between the spin-orbit split bands, in spite of the considerably large spin-orbit splitting. This is due to frustration between the spin-orbit interaction and pairing interactions. In this pairing state, time-reversal symmetry is restored, in contrast to the bulk Sr${}_2$RuO${}_4$ which is believed to be a chiral $p+ip$ superconductor with broken time-reversal symmetry. It is demonstrated that, because of these features, the pairing state at the interface is a promising candidate for the recently proposed time-reversal invariant topological superconductor.

Submitted to New. J. Phys. a focus issue on "Superconductors with Exotic Symmetries"; amended version as accepted for publication

References in corpus (14)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Classification of topological insulators and superconductors in three spatial dimensions
• Topological Superconductivity and Superfluidity
• Topological Phases of Noncentrosymmetric Superconductors: Edge States, Majorana Fermions, and the Non-Abelian Statistics
• S-wave/spin-triplet order in superconductors without inversion symmetry: Li${}_2$Pd${}_3$B and Li${}_2$Pt${}_3$B
• Spin Triplet Superconducting State due to Broken Inversion Symmetry in Li_2Pt_3B
• Topological spin-current in non-centrosymmetric superconductors
• Electron Correlation and Pairing States in Superconductors without Inversion Symmetry
• Edge solitons of topological insulators and fractionalized quasiparticles in two dimensions
• Surface bound states and spin currents in non-centrosymmetric superconductors
• Nodal Structure of Superconductors with Time-Reversal Invariance and Z2 Topological Number
• Fermi liquid theory for heavy fermion superconductors without inversion symmetry : Magnetism and transport coefficients
• Topological superfluids with time reversal symmetry

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• Zeeman field induced topological phase transitions in triplet superconductors
• Random Spin-orbit Coupling in Spin Triplet Superconductors: Stacking Faults in Sr_2RuO_4 and CePt_3Si
• Topological D+p-wave superconductivity in Rashba systems
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• Parity-mixing superconducting phase in the Rashba-Hubbard model and its topological properties from dynamical mean field theory
• Topological d-wave superconductivity in two dimensions
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• Theory of tunneling spectroscopy of normal metal/ferromagnet/spin-triplet superconductor junctions
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• Identification of Spin-Triplet Superconductivity through a Helical-Chiral Phase Transition in Sr${}_2$RuO${}_4$ Thin-Films
• Control of Edge Currents at a Ferromagnet - Triplet Superconductor Interface by Multiple Helical Majorana Modes
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