Charge solitons and their dynamical mass in 1-D arrays of Josephson junctions

TL;DR

This paper explores charge transport in 1D Josephson junction arrays, revealing how charge solitons behave and their effective mass scales with Josephson energy, using two theoretical methods for validation.

Contribution

It introduces a detailed analysis of small charge solitons and their dynamical mass, employing both many-body and mean-field approaches for the first time in this context.

Findings

Charge soliton mass scales as inverse square of Josephson energy.

Results from two different theoretical approaches agree in the small charge soliton regime.

Charge dynamics are significantly affected by polaronic effects in the array.

Abstract

We investigate the charge transport in one-dimensional arrays of Josephson junctions. In the interesting regime of "small charge solitons" (polarons), the charge dynamics is strongly influenced by the polaronic effects, i.e., by dressing of a Cooper pair by charge dipoles. In particular, the soliton's mass in this regime scales approximately as inverse square of the Josephson energy. We employ two theoretical techniques: the many body tight-binding approach and the mean-field approach. Results of the two approaches agree in the regime of "small charge solitons".