Dependence of the maximal superconducting current on resonance frequency in shunted Josephson junction

TL;DR

This study explores how the maximum superconducting current in shunted Josephson junctions varies with resonance frequency, revealing that the maximum current is optimized at specific frequencies and is largely independent of dissipation parameters.

Contribution

The paper provides a detailed analysis of the dependence of the maximal superconducting current on resonance frequency in Josephson junctions coupled to an LC circuit, highlighting conditions for optimal current.

Findings

Maximal superconducting current depends on resonance frequency.

Maximum current increases as the rc-branch endpoint approaches the critical current.

Optimal maximum current is nearly independent of system parameters within 1%.

Abstract

We have investigated the phase dynamics and IV-characteristics of shunted Josephson junctions coupled to an $LC$ circuit. When the Josephson frequency $\omega_J$ is close to the eigen frequency $\omega_{rc}$ of the coupled resonance circuit, the IV-characteristic demonstrates an additional $rc$-branch. We have investigated the features of the $rc$-branch and of the superconducting current component for different values of the resonance frequency. It has been found that the maximal value of the superconducting current depends on the resonance frequency and that it increases when the end point of the $rc$-branch approaches the critical current. The dependence of the maximal superconducting current on the resonance frequency at different values of the dissipation parameter is peculiar, for the optimized maximum appears to be independent of the system parameters within $1\%$.