Observation of breather-like states in a single Josephson cell

TL;DR

This paper reports the experimental detection of breather-like states in a superconducting loop with Josephson junctions, confirming theoretical predictions and analyzing their behavior under magnetic fields.

Contribution

It provides the first experimental observation of broken-symmetry breather-like states in a single Josephson cell, aligning with theoretical models.

Findings

Identification of breather-like states in Josephson loops

Resonant states observed in current-voltage characteristics

Dependence of resonances on external magnetic field

Abstract

We present experimental observation of broken-symmetry states in a superconducting loop with three Josephson junctions. These states are generic for discrete breathers in Josephson ladders. The existence region of the breather-like states is found to be in good accordance with the theoretical expectations. We observed three different resonant states in the current-voltage characteristics of the broken-symmetry state, as predicted by theory. The experimental dependence of the resonances on the external magnetic field is studied in detail.