# Proximity induced time-reversal topological superconductivity in Bi2Se3 films without phase tuning

## TL;DR

This paper demonstrates that a topological superconducting phase can be realized in Bi2Se3 thin films via proximity to a single s-wave superconductor, without the need for phase tuning, by leveraging interparity pairing and electric fields.

## Contribution

It shows that a topological phase can be achieved without phase tuning by inducing interparity pairing in Bi2Se3 films with a single superconductor.

## Key findings

- Topological phase can be reached with a single superconductor.
- Electric fields extend the topological phase range.
- Interparity pairing dominates over intraparity pairing.

## Abstract

Many proposals to generate a time-reversal invariant topological superconducting phase are based on imposing a $\pi$ phase difference between the superconducting leads proximitizing a nanostructure. We show that this phase can be induced on a thin film of a topological insulator like Bi$_2$Se$_3$ in proximity to a single s-wave superconductor. In our analysis we take into account the parity degree of freedom of the electronic states which is not included in effective Dirac-like surface theories. We find that the topological phase can be reached when the induced interparity pairing dominates over the intraparity one. Application of an electric field perpendicular to the film extends the range of parameters where the topological phase occurs.