Discrete breathers in dc biased Josephson-junction arrays

TL;DR

This paper introduces a method to excite and detect localized rotor modes in dc-biased Josephson-junction arrays, demonstrating their stability and broad parameter range, with potential for experimental observation.

Contribution

It presents a novel approach to generate and analyze rotobreathers in Josephson-junction arrays, including stability analysis and experimental feasibility.

Findings

Two families of stable rotobreathers identified

Rotobreathers stable under thermal fluctuations

Existence confirmed in small arrays including single plaquettes

Abstract

We propose a method to excite and detect a rotor localized mode (rotobreather) in a Josephson-junction array biased by dc currents. In our numerical studies of the dynamics we have used experimentally realizable parameters and included self-inductances. We have uncovered two families of rotobreathers. Both types are stable under thermal fluctuations and exist for a broad range of array parameters and sizes including arrays as small as a single plaquette. We suggest a single Josephson-junction plaquette as an ideal system to experimentally investigate these solutions.