Multiterminal Ballistic Josephson Effect in Monocrystalline Gold

TL;DR

This paper demonstrates a multiterminal Josephson effect in a monocrystalline gold system, revealing nonlocal supercurrent behavior and phase coherence across the entire crystal, supported by experimental and theoretical analysis.

Contribution

It introduces a novel multiterminal ballistic Josephson junction array using single-crystal gold, showing nonlocal supercurrent effects and phase coherence across multiple terminals.

Findings

Non-monotonic critical current dependence on junction length

Magnetic interference patterns match shared normal-metal area

Supercurrent depends on phase configuration of all electrodes

Abstract

We report on the realization of a planar, quasi-ballistic Josephson junction array using a Au micron-sized single-crystal. The system exhibits a nonlocal, multiterminal Josephson effect, where the supercurrent between any two superconducting leads is governed by the phase coherence across the entire crystal. Key evidence includes a non-monotonic dependence of the critical current on junction length and magnetic interference patterns with periods corresponding to the shared normal-metal area. Nonlocal transport measurements further confirm that the supercurrent between two electrodes depends on the phase configuration of all the others. Our results, supported by a developed theoretical model, establish a platform for exploring complex superconducting phenomena in multiterminal ballistic systems.