Interaction-driven topological superconductivity in one dimension

TL;DR

This paper explores one-dimensional topological superconductivity with time-reversal symmetry, presenting models and experimental setups to realize and study Majorana bound states in such systems, emphasizing the role of electron interactions.

Contribution

It introduces a simple model for interaction-driven topological superconductivity with time-reversal symmetry and proposes experimental setups to realize this phase.

Findings

Presence of Kramers' pairs of Majorana bound states at system ends.

Interaction effects can induce topological phases in the proposed models.

Experimental setups can realize and probe the topological superconducting phase.

Abstract

We study one-dimensional topological superconductivity in the presence of time-reversal symmetry. This phase is characterized by having a bulk gap, while supporting a Kramers' pair of zero-energy Majorana bound states at each of its ends. We present a general simple model which is driven into this topological phase in the presence of repulsive electron-electron interactions. We further propose two experimental setups and show that they realize this model at low energies. The first setup is a narrow two-dimensional topological insulator partially covered by a conventional s-wave superconductor, and the second is a semiconductor wire in proximity to an s-wave superconductor. These systems can therefore be used to realize and probe the time-reversal invariant topological superconducting phase. The effect of interactions is studied using both a mean-field approach and a renormalization group analysis.