Mapping the topological proximity-induced gap of multiterminal Josephson junctions

TL;DR

This paper demonstrates that resistance measurements in multiterminal Josephson junctions can reveal topological features through modulation of the quasiparticle density of states, providing a practical method to explore topological effects.

Contribution

It introduces a simple technique using resistance measurements to detect topological modulation in multiterminal Josephson junctions, advancing experimental exploration of topological phenomena.

Findings

Resistance of diffusive MTJJs varies with phase differences.

Resistance measurements reveal modulation of quasiparticle density of states.

Technique offers a practical way to explore topological effects in MTJJs.

Abstract

Multiterminal Josephson junctions (MTJJs), devices in which a normal metal is in contact with three or more superconducting leads, have been proposed as artificial analogs of topological crystals. The topological nature of MTJJs manifests as a modulation of the quasiparticle density of states (DOS) in the normal metal that may be probed by tunneling measurements. We show that one can reveal this modulation by measuring the resistance of diffusive MTJJs with normal contacts, which shows rich structure as a function of the phase differences $\{\phi_i \}$. Our approach demonstrates a simple yet powerful technique for exploring topological effects in MTJJs.