Interaction-induced negative mobility: realization in a system of two coupled Josephson junctions

TL;DR

This paper demonstrates that coupling two Josephson junctions can induce negative mobility and resistance phenomena, which do not occur in isolated overdamped systems, revealing new control mechanisms for transport properties.

Contribution

It introduces a realizable system of two coupled Josephson junctions showing negative mobility and resistance, highlighting the role of coupling in anomalous transport behaviors.

Findings

Second junction exhibits absolute negative resistance near zero bias.

Negative resistance occurs in nonlinear regimes for specific coupling values.

Transport properties can be controlled via the first junction.

Abstract

An overdamped dynamical system, biased by an external constant force, does not exhibit negative mobility. However, when the system is coupled to its copy, negative mobility can arise. We show it by the example of an experimentally realizable system of two coupled resistively shunted Josephson junctions. The first junction is dc-biased by a constant current and ac-driven by an unbiased harmonic current. In the proposed setup one can control the transport properties of the second junction by manipulating the first junction only. We demonstrate that the second junction can exhibit both absolute negative resistance (ANR) near zero bias and negative resistance in the non-linear regimes (NNR). These anomalous transport features occur for restricted windows of the coupling constant.