Enhanced zero-bias Majorana peak in disordered multi-subband quantum wires

TL;DR

This paper investigates how disorder and subband mixing in multi-subband quantum wires enhance the zero-bias Majorana peak, providing insights into experimental signatures of topological superconductivity.

Contribution

It demonstrates that disorder-induced subband mixing significantly amplifies the Majorana zero-bias peak in tunneling conductance, advancing understanding of Majorana detection in quantum wires.

Findings

Disorder enhances the Majorana zero-bias peak via subband mixing.

Topological phase transition affects the gap structure in conductance.

Zero-bias peak weight is strongly increased with disorder.

Abstract

A recent experiment [Mourik et al., Science 336, 1003 (2012)] on InSb quantum wires provides possible evidence for the realization of a topological superconducting phase and the formation of Majorana bound states. Motivated by this experiment, we consider the signature of Majorana bound states in the differential tunneling conductance of multi-subband wires. We show that the weight of the Majorana-induced zero-bias peak is strongly enhanced by mixing of subbands, when disorder is added to the end of the quantum wire. We also consider how the topological phase transition is reflected in the gap structure of the current-voltage characteristic.