Proximity-Induced Superconductivity at Non-Helical Topological Insulator Interfaces

Abstract

We study how non-helical spin textures at the boundary between a topological insulator (TI) and a superconductor (SC) affect the proximity-induced superconductivity of the TI interface state. We consider TIs coupled to both spin-singlet and spin-triplet SCs, and show that for the spin-triplet parent SCs the resulting order parameter induced onto the interface state sensitively depends on the symmetries which are broken at the TI-SC boundary. For chiral spin-triplet parent SCs, we find that nodal proximity-induced superconductivity emerges when there is broken twofold rotational symmetry which forces the spins of the non-helical topological states to tilt away from the interface plane. We furthermore show that the Andreev conductance of lateral heterostructures joining TI-vacuum and TI-SC interfaces yields experimental signatures of the reduced symmetries of the interface states.

arXiv comment5 pages, 2 figures

References in corpus (23)

• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Paired states of fermions in two dimensions with breaking of parity and time-reversal symmetries, and the fractional quantum Hall effect
• Spintronics and Pseudospintronics in Graphene and Topological Insulators
• Hexagonal Warping Effects in the Surface States of Topological Insulator Bi${}_2$Te${}_3$
• Superconductivity and spin-orbit coupling in non-centrosymmetric materials: a review
• Boundary conditions for Dirac fermions on a terminated honeycomb lattice
• Unconventional superconductivity on a topological insulator
• Symmetry of boundary conditions of the Dirac equation for electrons in carbon nanotubes
• Interplay between Superconductivity and Ferromagnetism on a Topological Insulator
• Hybridization at superconductor-semiconductor interfaces
• Proximity-induced unconventional superconductivity in topological insulators
• Odd-frequency superconducting pairing and subgap density of states at the edge of a two-dimensional topological insulator without magnetism
• Boundary problems for Dirac electrons and edge-assisted Raman scattering in graphene
• Conductance signatures of odd-frequency superconductivity in quantum spin Hall systems using a quantum point contact
• Symmetry and topology of two-dimensional noncentrosymmetric superconductors
• Observability of surface Andreev bound states in a topological insulator in proximity to an s-wave superconductor
• Mott scattering at the interface between a metal and a topological insulator
• On the Role of Self-Adjointness in the Continuum Formulation of Topological Quantum Phases
• Interface symmetry and spin control in topological insulator-semiconductor heterostructures
• Tunable unconventional Kondo effect on topological insulator surfaces
• A Numerical Study of the Superconducting Proximity Effect in Topological Surface States

Cited by in corpus (5)

• Volkov-Pankratov states in topological superconductors
• Conductance of gated junctions as a probe of topological interface states
• Andreev spectroscopy of nonhelical spin textures in topological insulators
• Particle-hole asymmetry and quantum confinement effects on the magneto-optical response of topological insulator thin-films
• Local density of state oscillations in laterally heterostructured topological insulator-semiconductor systems