Majorana states in a p-wave superconducting ring

TL;DR

This paper investigates the excitation spectrum of a chiral p-wave superconducting ring, revealing the existence of stable zero-energy Majorana states that can be tuned via a resonance condition, despite not being topologically protected.

Contribution

It demonstrates the presence of stable zero-energy Majorana states in a superconducting ring and discusses how to tune the system into a Majorana disk state.

Findings

Existence of a pair of zero-energy states in the ring.

Zero-energy states are stable under certain deformations.

Tuning conditions resemble a resonance phenomenon.

Abstract

The spectrum of excitations of the chiral superconducting ring with internal and external radii, comparable with coherence length, trapping a unit flux is calculated. We find within the Bogoliubov-deGennes approach that there exists a pair of precisely zero energy states. They are not protected by topology, but are stable under certain deformations of the system. We discuss the ways to tune the system so that it grows into such a "Majorana disk". This condition has a character of a resonance phenomenon.