Proximity effect at the superconductor - topological insulator interface

Tudor D. Stanescu; Jay D. Sau; Roman M. Lutchyn; S. Das Sarma

doi:10.1103/physrevb.81.241310

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arXiv · 1002.0842

Proximity effect at the superconductor - topological insulator interface

Tudor D. Stanescu·Jay D. Sau·Roman M. Lutchyn·S. Das Sarma

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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.

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Tudor D. Stanescu, Jay D. Sau, Roman M. Lutchyn, S. Das Sarma. 2010-02-03. Proximity effect at the superconductor - topological insulator interface. https://doi.org/10.1103/physrevb.81.241310

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