Signatures of the topological spin of Josephson vortices in topological superconductors

TL;DR

This paper investigates how the topological spin of Josephson vortices influences the Aharonov-Casher phase in topological superconductors, revealing a universal phase related to vortex parity and topological invariants.

Contribution

It introduces a modified measurement setup that uncovers a universal topological phase linked to vortex parity and spin, advancing understanding of topological superconducting states.

Findings

Discovered a universal topological phase depending on vortex parity.

Linked the phase to the topological spin and Chern number.

Proposed a measurable effect on junction voltage characteristics.

Abstract

We consider a modified setup for measuring the Aharonov-Casher phase which consists of a Josephson vortex trapped in an annular topological superconducting junction. The junction encloses both electric charge and magnetic flux. We discover a deviation from the Aharonov-Casher prediction whose origin we identify in an additive universal topological phase that remarkably depends only on the parity of the number of vortices enclosed by the junction. We show that this phase is $\pm 2\pi$ times the topological spin of the Josephson vortex and is proportional to the Chern number. The presence of this phase can be measured through its effect on the junction's voltage characteristics, thus revealing the topological properties of the Josephson vortex and the superconducting state.