Anomalous transport in biased ac-driven Josephson junctions: Negative conductances

TL;DR

This paper explores how a driven Josephson junction exhibits various anomalous electrical transport phenomena, including negative conductance, under chaotic conditions with combined ac and dc currents.

Contribution

It reveals novel negative conductance effects in a classical Josephson junction driven by both ac and dc currents, expanding understanding of non-equilibrium transport behaviors.

Findings

Identification of absolute negative conductance near zero dc-bias

Observation of negative differential conductance regimes

Discovery of negative nonlinear conductance in non-equilibrium conditions

Abstract

We investigate classical anomalous electrical transport in a driven, resistively and capacitively shunted Josephson junction device. Novel transport phenomena are identified in chaotic regimes when the junction is subjected to both, a time periodic (ac) and a constant, biasing (dc) current. The dependence of the voltage across the junction on the dc-current exhibits a rich diversity of anomalous transport characteristics: In particular, depending on the chosen parameter regime we can identify so termed absolute negative conductance around zero dc-bias, the occurrence of negative differential conductance and, after crossing a zero conductance, the emergence of a negative nonlinear conductance in the non-equilibrium response regime remote from zero dc-bias.