Tailoring Josephson coupling through superconductivity-induced nonequilibrium

TL;DR

This paper proposes using nonequilibrium quasiparticle distributions in a superconductor-insulator-normal metal-insulator-superconductor (SINIS) structure to precisely control the supercurrent in a Josephson junction, enabling tunable superconducting devices.

Contribution

It introduces a novel method to tailor Josephson coupling by exploiting nonequilibrium effects in a SINIS setup, analyzed through quasiclassical Green-function theory with inelastic scattering.

Findings

Supercurrent can be enhanced or suppressed via nonequilibrium control.

Transition to a $$-junction is achievable.

The method allows full tunability of the Josephson weak link.

Abstract

The distinctive quasiparticle distribution existing under nonequilibrium in a superconductor-insulator-normal metal-insulator-superconductor (SINIS) mesoscopic line is proposed as a novel tool to control the supercurrent intensity in a long Josephson weak link. We present a description of this system in the framework of the diffusive-limit quasiclassical Green-function theory and take into account the effects of inelastic scattering with arbitrary strength. Supercurrent enhancement and suppression, including a marked transition to a $\pi$-junction are striking features leading to a fully tunable structure.