Mesoscopic supercurrent transistor controlled by nonequilibrium cooling

TL;DR

This paper proposes a novel mesoscopic supercurrent transistor controlled by nonequilibrium cooling, utilizing quasiparticle distributions in a SINIS structure to achieve tunable supercurrent and $ ext{π}$-junction transitions.

Contribution

It introduces a new control mechanism for supercurrent in Josephson junctions using nonequilibrium quasiparticle distributions analyzed via Green-function theory.

Findings

Supercurrent can be enhanced or suppressed through nonequilibrium control.

The system exhibits a transition to a $ ext{π}$-junction, enabling full tunability.

Factors like temperature, material choice, and noise influence device performance.

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. The role of the degree of nonequilibrium, temperature, and materials choice as well as features like noise, switching time, and current and power gain are also addressed.