Proximity effect at the superconductor - topological insulator interface
Abstract
We study the excitation spectrum of a topological insulator in contact with an s-wave superconductor, starting from a microscopic model, and develop an effective low-energy model for the proximity effect. In the vicinity of the Dirac cone vertex, the effective model describing the states localized at the interface is well approximated by a model of Dirac electrons experiencing superconducting s-wave pairing. Away from the cone vertex, the induced pairing potential develops a p-wave component with a magnitude sensitive to the structure of the interface. Observing the induced s-wave superconductivity may require tuning the chemical potential close to the Dirac point. Furthermore, we find that the proximity of the superconductor leads to a significant renormalization of the original parameters of the effective model describing the surface states of a topological insulator.
Cite
@article{arxiv.1002.0842,
title = {Proximity effect at the superconductor - topological insulator interface},
author = {Tudor D. Stanescu and Jay D. Sau and Roman M. Lutchyn and S. Das Sarma},
journal= {arXiv preprint arXiv:1002.0842},
year = {2010}
}
Comments
4+ pages, 3 figures (published version)