Manipulation and Generation of Supercurrent in Out-of-Equilibrium Josephson Tunnel Nanojunctions

TL;DR

This paper experimentally manipulates supercurrent in Josephson tunnel junctions by quasiparticle injection, achieving both enhancement and quenching, and demonstrates cooling of the Ti island through non-equilibrium techniques.

Contribution

It introduces a method to control supercurrent in Josephson junctions via quasiparticle injection and provides a theoretical model explaining the observed phenomena.

Findings

Supercurrent can be enhanced or quenched by quasiparticle injection.

Cooling of the Ti island is achieved through quasiparticle injection.

A heat transport model explains the non-monotonic current-voltage behavior.

Abstract

We demonstrate experimentally manipulation of supercurrent in Al-AlO_x-Ti Josephson tunnel junctions by injecting quasiparticles in a Ti island from two additional tunnel-coupled Al superconducting reservoirs. Both supercurrent enhancement and quenching with respect to equilibrium are achieved. We demonstrate cooling of the Ti line by quasiparticle injection from the normal state deep into the superconducting phase. A model based on heat transport and non-monotonic current-voltage characteristic of a Josephson junction satisfactorily accounts for our findings.