Identify the topological superconducting order in a multi-band quantum wire

TL;DR

This paper proposes a method to identify topological superconducting order in a multi-band quantum wire by analyzing tunneling conductance patterns in a Josephson junction, distinguishing topological from trivial phases.

Contribution

It introduces a phase-sensitive tunneling conductance measurement technique to detect topological superconductivity in quantum wires.

Findings

Conductance peak at phase difference $$ indicates topological phase.

Butterfly pattern in conductance helps distinguish phases.

Method can differentiate Majorana-induced ZBPs from other effects.

Abstract

How to distinguish the zero-bias peak (ZBP) caused by the Majorana fermions from that by the other effects remains a challenge in detecting the topological order of a quantum wire. In this paper we propose to distinguish the topological superconducting phase from the topologically trivial phase by making a Josephson junction of the quantum wire attached to a side lead and then measuring the tunneling conductance through it as the phase difference across the junction $\phi$ varies. Even if the ZBPs exist in both phases, we can identify the topological superconducting phase by a conductance peak at $\phi=\pi$ and a nearby butterfly pattern.