Interplay between singlet and triplet pairings in multi-band two-dimensional oxide superconductors

Abstract

We theoretically study the superconducting properties of multi-band two-dimensional transition metal oxide superconductors by analyzing not only the role played by conventional singlet pairings, but also by the triplet order parameters, favored by the spin-orbit couplings present in these ma- terials. In particular, we focus on the two-dimensional electron gas at the (001) interface between LaAlO3 and SrTiO3 band insulators where the low electron densities and the sizeable spin-orbit couplings affect the superconducting features. Our theoretical study is based on an extended su- perconducting mean-field analysis of the typical multi-band tight-binding Hamiltonian, as well as on a parallel analysis of the effective electronic bands in the low-momentum limit, including static on-site and inter-site intra-band attractive potentials under applied magnetic fields. The presence of triplet pairings is able to strongly reduce the singlet order parameters which, as a result, are no longer a monotonic function of the charge density. The interplay between the singlet and the triplet pairings affects the dispersion of quasi-particle excitations in the Brillouin zone and also induces anisotropy in the superconducting behavior under the action of an in-plane and of an out- of-plane magnetic fields. Finally, non-trivial topological superconducting states become stable as a function of the charge density, as well as of the magnitude and of the orientation of the magnetic field. In addition to the chiral, time-reversal breaking, topological superconducting phase, favored by the linear Rashba couplings and by the on-site attractive potentials in the presence of an out- of-plane magnetic field, we find that a time-reversal invariant topological helical superconducting phase is promoted by not-linear spin-orbit couplings and by the inter-site attractive interactions in the absence of magnetic field.

References in corpus (61)

• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Classification of topological quantum matter with symmetries
• Topological superconductors: a review
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Superconducting 2D system with lifted spin degeneracy: Mixed singlet-triplet state
• Superconductivty without inversion symmetry: MnSi versus CePt_3Si
• Topological Superconductivity and Superfluidity
• Tuning spin-orbit coupling and superconductivity at the SrTiO3/LaAlO3 interface: a magneto-transport study
• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
• Scattering and Pairing in Cuprate Superconductors
• A Universal Critical Density Underlying the Physics of Electrons at the LaAlO3/SrTiO3 Interface
• Classification of Topological Insulators and Superconductors
• Orbital reconstruction and two-dimensional electron gas at the LaAlO3/SrTiO3 interface
• Non-Abelian Topological Orders and Majorana Fermions in Spin-Singlet Superconductors
• Two-dimensional superconductivity at a Mott-Insulator/Band-Insulator interface: LaTiO3/SrTiO3
• Superconductivity and Ferromagnetism in Oxide Interface Structures: Possibility of Finite Momentum Pairing
• Finite temperature phase diagram of a polarised Fermi condensate
• BEC-BCS crossover, phase transitions and phase separation in polarized resonantly-paired superfluids
• Superconductivity of doped Weyl semimetals: finite-momentum pairing and electronic analogues of the 3He-A phase
• Quantum critical origin of the superconducting dome in SrTiO${}_3$
• Common Fermi-liquid origin of T-squared resistivity and superconductivity in n-type SrTiO3
• Topological surface states in nodal superconductors
• Polaronic metal state at the LaAlO3/SrTiO3 interface
• Theory of t2g electron-gas Rashba interactions
• Surface density of states and topological edge states in non-centrosymmetric superconductors
• Superconductivity at very low density: the case of strontium titanate
• Topological superconductivity and unconventional pairing in oxide interfaces
• Two-dimensional electron liquid state at LaAlO3-SrTiO3 interfaces
• Nodal Structure of Superconductors with Time-Reversal Invariance and Z2 Topological Number
• Cubic spin-orbit coupling and anomalous Josephson effect in planar junctions
• Spin Orbit coupling and Anomalous Josephson effect in Nanowires
• Giant negative magnetoresistance driven by spin-orbit coupling at the LAO/STO interface
• Strong correlations elucidate the electronic structure and phase-diagram of LaAlO3/SrTiO3 interface
• Phase separation from electron confinement at oxide interfaces
• Link between the Superconducting Dome and Spin-Orbit Interaction in the (111) LaAlO${}_3$/SrTiO${}_3$ Interface
• Unconventional multi-band superconductivity in bulk SrTiO${}_3$ and LaAlO${}_3$/SrTiO${}_3$ interfaces
• Competition between electron pairing and phase coherence in superconducting interfaces
• Anomalous Josephson Effect in S/SO/F/S heterostructures
• Superconductivity with Rashba Spin-Orbit Coupling and Magnetic Field
• Route to Topological Superconductivity via Magnetic Field Rotation
• Topological superconductivity and Majorana bound states at the LaAlO${}_3$/SrTiO${}_3$ interface
• Inter-orbital topological superconductivity in spin-orbit coupled superconductors with inversion symmetry breaking
• Enhanced critical temperature, pairing fluctuation effects, and BCS-BEC crossover in a two-band Fermi gas
• Multi-Orbital Superconductivity in SrTiO3 /LaAlO3 Interface and SrTiO3 Surface
• Band inversion driven by electronic correlations at the (111) LaAlO${}_3$/SrTiO${}_3$ interface
• Modulation of the superconducting critical temperature due to quantum confinement at the LaAlO${}_3$/SrTiO${}_3$ interface
• Ultracold atoms in a square lattice with spin-orbit coupling: Charge order, superfluidity, and topological signatures
• Evolution of topological superconductivity by orbital selective confinement in oxide nanowires
• Superconductivity induced by fluctuations of momentum-based multipoles
• Symmetry and topology of two-dimensional noncentrosymmetric superconductors
• Tuning Rashba spin-orbit coupling at LaAlO3/SrTiO3 interfaces by band filling
• Unveiling Signatures of Topological Phases in Open Kitaev Chains and Ladders
• Multi-band theory of superconductivity at the LaAlO${}_3$/SrTiO${}_3$ interface
• Superconducting dome in the LaAlO${}_3$/SrTiO${}_3$ interfaces as a direct effect of the extended s-wave symmetry of the gap
• Intra-valley Spin-triplet $p+ip$ Superconducting Pairing in Lightly Doped Graphene
• Fermionic boundary modes in two-dimensional noncentrosymmetric superconductors
• Spin-orbital polarization of Majorana edge states in oxides nanowires
• Domes of $T_c$ in single-band and multiband superconductors with finite-range attractive interactions
• Ground state features and spectral properties of large polaron liquids from low to high charge densities
• Superconducting dome in doped 2D superconductors with broken inversion symmetry
• Synthesis of Majorana mass terms in low-energy quantum systems

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• Lindblad master equation approach to the dissipative quench dynamics of planar superconductors
• Gate tunable anomalous Hall effect: a Berry curvature probe at oxides interfaces
• Interplay between the extended s-wave symmetry of the gap and the spin-orbit coupling in the low-electron concentration regime of quasi-two-dimensional superconductors
• Spin-Hall Current and Nonlocal Transport in Ferromagnet-Free Multi-band models for SrTiO3-Based Nanodevices in the presence of impurities
• Pairing symmetries in the Zeeman-coupled extended attractive Hubbard model