Mapping the Topological Phase Diagram of Multiband Semiconductors with Supercurrents

TL;DR

This paper demonstrates that the critical supercurrent in multiband semiconductor Josephson junctions reveals the topological phase diagram, enabling a direct dc measurement of Majorana bound states through supercurrent behavior.

Contribution

It introduces a method to map the topological phases of multiband semiconductors using supercurrent measurements, linking Josephson junction properties to topological states.

Findings

Strong even-odd effects in critical current indicate Majorana states.

Critical supercurrent maps the topological phase diagram.

Method provides a dc measurement of topological transitions.

Abstract

We show that Josephson junctions made of multiband semiconductors with strong spin-orbit coupling carry a critical supercurrent $I_c$ that contains information about the non-trivial topology of the system. In particular, we find that the emergence and annihilation of Majorana bound states in the junction is reflected in strong even-odd effects in $I_c$ at small junction transparency. This effect allows for a mapping between $I_c$ and the topological phase diagram of the junction, thus providing a dc measurement of its topology.