Negative conductance in driven Josephson junctions

TL;DR

This paper explores the conditions under which a Josephson junction exhibits negative conductance when driven by combined ac and dc currents, analyzing stability and current-voltage characteristics.

Contribution

It identifies the optimal regime for negative conductance in driven Josephson junctions and examines the stability of this negative response.

Findings

Negative conductance occurs in specific driven regimes.

Stability of negative conductance depends on ac-current frequency.

Current-voltage characteristics reveal conditions for negative conductance.

Abstract

We investigate an optimal regime of negative-valued conductance, emerging in a resistively and capacitively shunted Josephson junction, which is driven simultaneously by both, a time-periodic (ac) and a constant (dc) current. We analyze the current-voltage characteristics in the regime of absolute negative conductance. We additionally explore the stability of the negative response with respect to the ac-current frequency.