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.

4+ pages, 3 figures (published version)

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Cited by in corpus (6)

• Non-Abelian quantum order in spin-orbit-coupled semiconductors: The search for topological Majorana particles in solid state systems
• Tunneling of anyonic Majorana excitations in topological superconductors
• Interface Between Topological and Superconducting Qubits
• Topologically non-trivial superconductivity in spin-orbit coupled systems: Bulk phases and quantum phase transitions
• Robustness of Majorana Modes and Minigaps in a Spin-Orbit-Coupled Semiconductor-Superconductor Heterostructure
• Mott scattering at the interface between a metal and a topological insulator