Fermion zero modes at the boundary of superfluid 3He-B

TL;DR

This paper discusses the existence of Majorana fermion zero modes at the surface of superfluid 3He-B, a topological superfluid, and their potential detection in experiments involving vibrating wires.

Contribution

It identifies Majorana fermion zero modes at the boundary of superfluid 3He-B and suggests experimental methods to detect them.

Findings

Majorana fermions exist as zero modes at the surface of 3He-B.

Rough surfaces lead to a finite density of states at zero energy.

Experiments with vibrating wires may have already observed these Majorana modes.

Abstract

Superfluid 3He-B belongs to the important special class of time-reversal invariant topological superfluids. It has Majorana fermions as edge states on the surface of bulk 3He-B. On the rough wall these fermion zero modes have finite density of states at E=0. It is possible that Lancaster experiments with a wire vibrating in 3He-B have already probed Majorana fermions living on the surface of the wire.