A Green's function approach to topological insulator junctions with magnetic and superconducting regions.

J Phys Condens Matter

Departamento de Física, Universidad Nacional de Colombia, Bogotá, Colombia.

Published: September 2020

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 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 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.

Download full-text PDF

Source
http://dx.doi.org/10.1088/1361-648X/abafc9DOI Listing

Publication Analysis

Top Keywords

green's function
8
function approach
8
topological insulator
8
green's functions
8
green's
4
approach topological
4
insulator junctions
4
junctions magnetic
4
magnetic superconducting
4
superconducting regions
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!