Inducing time reversal invariant topological superconductivity and fermion parity pumping in quantum wires

TL;DR

This paper proposes a method to realize time-reversal invariant topological superconductors in quantum wires with strong spin-orbit coupling, demonstrating Majorana modes and fermion parity pumping through phase control of coupled superconductors.

Contribution

It introduces a novel setup for topological superconductivity in quantum wires with phase-controlled Majorana modes and fermion parity pumping, advancing experimental realization prospects.

Findings

Majorana zero modes appear at edges when phase difference is π.

System exhibits robustness against certain perturbations.

Fermion parity can be pumped by adiabatically changing phase.

Abstract

We propose a setup to realize time-reversal invariant topological superconductors in quantum wires, proximity coupled to conventional superconductors. We consider a model of quantum wire with strong spin-orbit coupling and proximity coupling to two s-wave superconductors. When the relative phase between the two superconductors is $\phi=\pi$ a Kramers' pair of Majorana zero modes appears at each edge of the wire. We study the robustness of the phase in presence of both time-reversal invariant and time-reversal breaking perturbations. In addition, we show that the system forms a natural realization of a fermion parity pump, switching the local fermion parity of both edges when the relative phase between the superconductors is changed adiabatically by $2\pi$.