Multiplet supercurrent in Josephson tunneling circuits

TL;DR

This paper demonstrates that standard tunnel Josephson circuits can support multiplet supercurrents through local tunneling, persisting in high charging energy regimes and featuring a quantum geometric component distinct from adiabatic effects.

Contribution

It reveals that multiplet supercurrents can arise in conventional Josephson circuits via local processes, including in regimes previously thought unfavorable, and identifies a quantum geometric contribution.

Findings

Multiplet supercurrents exist in standard tunnel Josephson circuits.

Supercurrents persist even in high charging energy regimes.

A quantum geometric component of supercurrent is identified.

Abstract

The multi-terminal Josephson effect allows DC supercurrent to flow at finite commensurate voltages. Existing proposals to realize this effect rely on nonlocal Andreev processes in superconductor-normal-superconductor junctions. However, this approach requires precise control over microscopic states and is obscured by dissipative current. We show that standard tunnel Josephson circuits also support multiplet supercurrent mediated only by local tunneling processes. Furtheremore, we observe that the supercurrents persist even in the high charging energy regime in which only sequential Cooper transfers are allowed. Finally, we demonstrate that the multiplet supercurrent in these circuits has a quantum geometric component that is distinguinshable from the well-known adiabatic contribution.