Mesoscopic Josephson Effect

TL;DR

This paper explores the behavior of mesoscopic Josephson junctions, analyzing how quantum fluctuations and Coulomb blockade effects influence supercurrent and current-voltage characteristics across different regimes.

Contribution

It provides a comprehensive analysis of mesoscopic Josephson effects, including quantum fluctuations and Coulomb blockade, extending understanding beyond classical Josephson behavior.

Findings

Quantum fluctuations significantly affect supercurrent in mesoscopic junctions.

Coulomb blockade leads to suppression of Cooper pair tunneling.

Current-voltage characteristics vary markedly across different regimes.

Abstract

In the classical Josephson effect the phase difference across the junction is well defined, and the supercurrent is reduced only weakly by phase diffusion. For mesoscopic junctions with small capacitance the phase undergoes large quantum fluctuations, and the current is also decreased by Coulomb blockade effects. We discuss the behavior of the current-voltage characteristics in a large range of parameters comprising the phase diffusion regime with coherent Josephson current as well as the supercurrent peak due to incoherent Cooper pair tunneling in the Coulomb blockade regime.