A Green's function approach to Topological Insulator junctions with magnetic and superconducting regions

Abstract

This work presents a Green's function approach, originally implemented in graphene with well-defined edges, to the surface of a strong 3D Topological Insulator (TI) with a sequence of proximitized superconducting (S) and ferromagnetic (F) surfaces. This consists of the derivation of the Green's functions for each region by the asymptotic solutions method, and their coupling by a tight-binding Hamiltonian with the Dyson equation to obtain the full Green's functions of the system. These functions allow the direct calculation of the momentum-resolved spectral density of states, the identification of subgap interface states, and the derivation of the differential conductance for a wide variety of configurations of the junctions. We illustrate the application of this method for some simple systems with two and three regions, finding the characteristic chiral state of the Quantum Anomalous Hall Effect (QAHE) at the NF interfaces, and chiral Majorana modes at the NS interfaces. Finally, we discuss some geometrical effects present in three-region junctions such as weak Fabry-Pérot resonances and Andreev bound states.

arXiv comment14 pages, 6 figures

References in corpus (51)

• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• Topological Field Theory of Time-Reversal Invariant Insulators
• Topological Insulator Materials
• Josephson Current and Noise at a Superconductor-Quantum Spin Hall Insulator-Superconductor Junction
• Model Hamiltonian for Topological Insulators
• Specular Andreev reflection in graphene
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Observation of Majorana fermions with spin selective Andreev reflection in the vortex of topological superconductor
• Majorana mode in vortex core of Bi2Te3/NbSe2 topological insulator-superconductor heterostructure
• Hamiltonian approach to the transport properties of superconducting quantum point contacts
• Manipulation of Majorana fermion, Andreev reflection and Josephson current on topological insulators
• Observation of topological surface state quantum Hall effect in an intrinsic three-dimensional topological insulator
• Unconventional superconductivity on a topological insulator
• Electrically tunable surface-to-bulk coherent coupling in topological insulator thin films
• Thickness-dependent bulk properties and weak anti-localization effect in topological insulator Bi2Se3
• Andreev bound states in high-$T_c$ superconducting junctions
• Tunable Surface Conductivity in Bi2Se3 Revealed in Diffusive Electron Transport
• High-Field Shubnikov-de Haas Oscillations in the Topological Insulator Bi${}_2$Te${}_2$Se
• Quantum Hall Effect on Top and Bottom Surface States of Topological Insulator (Bi1-xSbx)2Te3 Films
• Interplay between Superconductivity and Ferromagnetism on a Topological Insulator
• Magnetoelectrics in Disordered Topological Insulator Josephson Junctions
• Josephson Junction through a Disordered Topological Insulator with Helical Magnetization
• Superconducting proximity effect in three-dimensional topological insulators in the presence of a magnetic field
• Helical Andreev bound states and superconducting Klein tunneling in topological insulator Josephson junctions
• Andreev bound states and current-phase relations in three-dimensional topological insulators
• Spontaneous supercurrent and $\varphi$0 phase shift parallel to magnetized topological insulator interfaces
• Magnetotransport of Dirac Fermions on the surface of a topological insulator
• Spintronics and spincaloritronics in topological insulators
• Observation of perfect Andreev reflection due to Klein paradox in a topological superconducting state
• Spin and Charge Structure of the Surface States in Topological Insulators
• Shubnikov-de Haas oscillations from topological surface states of metallic Bi${}_2$Se${}_{2.1}$Te${}_{0.9}$
• Josephson and proximity effects on the surface of a topological insulator
• Electronic States of Wires and Slabs of Topological Insulators: Quantum Hall Effects and Edge Transport
• Dirac Green's function approach to graphene-superconductor junctions with well defined edges
• Anomalous Josephson effect in d-wave superconductor junctions on TI surface
• Proximity induced interface bound states in superconductor-graphene junctions
• Coexistence of bulk and surface states probed by Shubnikov-de Haas oscillations in Bi${}_2$Se${}_3$ with high charge-carrier density
• Observability of surface Andreev bound states in a topological insulator in proximity to an s-wave superconductor
• Subgap states in two dimensional spectroscopy of unconventional superconductors using graphene
• Spintronic signatures of Klein tunneling in topological insulators
• Shubnikov-de Haas oscillations in p and n-type topological insulator (Bi${}_x$Sb${}_{1-x}$)${}_2$Te${}_3$
• Quantum critical point in the superconducting transition on the surface of topological insulator
• Dirac point formation revealed by Andreev tunneling in superlattice-graphene/superconductor junctions
• Interface electronic structure at the topological insulator - ferrimagnetic insulator junction
• Nearly flat Andreev bound states in superconductor-topological insulator hybrid structures
• Transport in Selectively Magnetically Doped Topological Insulator Wires
• Quasiparticle cooling using a Topological insulator-Superconductor hybrid junction

Cited by in corpus (2)

• Microscopic Green's function approach for generalized Dirac Hamiltonians
• Long-range Cooper pair splitting by chiral Majorana edge states