One-dimensional Josephson junction arrays: Lifting the Coulomb blockade by depinning

TL;DR

This paper investigates how the Coulomb blockade in one-dimensional Josephson junction arrays is lifted at a threshold voltage, explained through a disordered sine-Gordon model related to charge density wave de-pinning.

Contribution

It introduces a theoretical framework based on charge density wave de-pinning to explain Coulomb blockade lifting in disordered Josephson arrays, aligning well with experimental results.

Findings

Threshold voltage scales with array length

Strong dependence on Josephson energy

Model matches experimental data

Abstract

Experiments with one-dimensional arrays of Josephson junctions in the regime of dominating charging energy show that the Coulomb blockade is lifted at the threshold voltage, which is proportional to the array's length and depends strongly on the Josephson energy. We explain this behavior as de-pinning of the Cooper-pair-charge-density by the applied voltage. We assume strong charge disorder and argue that physics around the de-pinning point is governed by a disordered sine-Gordon-like model. This allows us to employ the well-known theory of charge density wave de-pinning. Our model is in good agreement with the experimental data.