Evolution of topological superconductivity by orbital selective confinement in oxide nanowires

Abstract

We determine the optimal conditions to achieve topological superconducting phases having spin-singlet pairing for a planar nanowire with finite lateral width in the presence of an in-plane external magnetic field. We employ a microscopic description that is based on a three-band electronic model including both the atomic spin-orbit coupling and the inversion asymmetric potential at the interface between oxide band-gap insulators. We consider amplitudes of the pairing gap, spin-orbit interactions and electronic parameters that are directly applicable to nanowires of LaAlO${}_3$-SrTiO${}_3$. The lateral confinement introduces a splitting of the $d$-orbitals that alters the orbital energy hierarchy and significantly affects the electron filling dependence of the topological phase diagram. Due to the orbital directionality of the $t_{2g}$-states, we find that in the regime of strong confinement the onset of topological phases is pinned at electron filling where the quasi flat heavy bands start to get populated. The increase of the nanowire thickness leads to a changeover from sparse-to-dense distribution of topologically non-trivial domains which occurs at the cross-over associated to the orbital population inversion. These findings are corroborated by a detailed analysis of the most favorable topological superconducting phases in the electron doping-magnetic field plane highlighting the role of orbital selective confinement.

arXiv comment13 pages, 8 figures, submitted

References in corpus (46)

• Topological insulators and superconductors
• Unpaired Majorana fermions in quantum wires
• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Helical liquids and Majorana bound states in quantum wires
• A generic new platform for topological quantum computation using semiconductor heterostructures
• Non-Abelian statistics and topological quantum information processing in 1D wire networks
• Topological superconductors: a review
• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Majorana Zero Modes and Topological Quantum Computation
• Exponential Protection of Zero Modes in Majorana Islands
• Majorana bound states in a coupled quantum-dot hybrid-nanowire system
• Tunable Rashba spin-orbit interaction at oxide interfaces
• Realizing Majorana zero modes in superconductor-semiconductor heterostructures
• Observation of topological superconductivity on the surface of an iron-based superconductor
• Quantized Majorana conductance
• Majorana Fermions in Semiconductor Nanowires: Fundamentals, Modeling, and Experiment
• Observation of topological order in a Superconducting doped topological insulator (based on the Bi2Se3 class)
• Tuning spin-orbit coupling and superconductivity at the SrTiO3/LaAlO3 interface: a magneto-transport study
• Majorana Fermions and Topology in Superconductors
• Theory of spin-orbit coupling at LaAlO3/SrTiO3 interfaces and SrTiO3 surfaces
• A Universal Critical Density Underlying the Physics of Electrons at the LaAlO3/SrTiO3 Interface
• Multichannel Generalization of Kitaev's Majorana End States and a Practical Route to Realize Them in Thin Films
• Physics of SrTiO${}_3$-based heterostructures and nanostructures: a review
• Search for Majorana fermions in multiband semiconducting nanowires
• Superconductivity and Ferromagnetism in Oxide Interface Structures: Possibility of Finite Momentum Pairing
• Majorana Zero Modes in 1D Quantum Wires Without Long-Ranged Superconducting Order
• Efficient numerical computation of the Pfaffian for dense and banded skew-symmetric matrices
• Theory of t2g electron-gas Rashba interactions
• Majorana bound states without vortices in topological superconductors with electrostatic defects
• Topological superconductivity and unconventional pairing in oxide interfaces
• Topologically non-trivial superconductivity in spin-orbit coupled systems: Bulk phases and quantum phase transitions
• Magnetic-field instability of Majorana modes in multiband quantum wires
• Magnetic and Superconducting Ordering at LaAlO3/SrTiO3 Interfaces
• Spin polarization of electrons with Rashba double-refraction
• Rashba quantum wire: exact solution and ballistic transport
• Competition Between Kondo Screening and Magnetism at the LaAlO${}_3$/SrTiO${}_3$ Interface
• One-Dimensional Nature of Pairing and Superconductivity at the LaAlO${}_3$/SrTiO${}_3$ Interface
• Topological states at the (001) surface of SrTiO3
• Superconductivity with Rashba Spin-Orbit Coupling and Magnetic Field
• Route to Topological Superconductivity via Magnetic Field Rotation
• Inter-orbital topological superconductivity in spin-orbit coupled superconductors with inversion symmetry breaking
• Topological superconductivity and Majorana bound states at the LaAlO${}_3$/SrTiO${}_3$ interface
• Multi-Orbital Superconductivity in SrTiO3 /LaAlO3 Interface and SrTiO3 Surface
• Multi-band theory of superconductivity at the LaAlO${}_3$/SrTiO${}_3$ interface
• Testing the formation of Majorana states using the Majorana Polarization

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• Gate tunable anomalous Hall effect: a Berry curvature probe at oxides interfaces
• Probing Topological Superconductivity of oxide nanojunctions using fractional Shapiro steps
• Quantized critical supercurrent in SrTiO${}_3$-based quantum point contacts
• Interplay between singlet and triplet pairings in multi-band two-dimensional oxide superconductors
• Spin-orbital polarization of Majorana edge states in oxides nanowires
• Strain-induced topological phase transition at (111) SrTiO${}_3$-based heterostructures
• Ballistic transport through quantum point contacts of multi-orbital oxides
• Effect of confinement and Coulomb interactions on the electronic structure of (111) LaAlO${}_3$/SrTiO${}_3$ interface
• Spin-Hall Current and Nonlocal Transport in Ferromagnet-Free Multi-band models for SrTiO3-Based Nanodevices in the presence of impurities
• Exponential suppression of the topological gap in self-consistent intrinsic Majorana nanowires
• Spin Hall and Edelstein effects in a ballistic quantum dot with Rashba spin-orbit coupling