Phase-Charge Duality of a Josephson junction in a fluctuating electromagnetic environment

TL;DR

This paper experimentally demonstrates the phase-charge duality in a Josephson junction within a high impedance environment, showing how overdamped quasicharge dynamics lead to Coulomb blockade and Bloch oscillations, with results matching theoretical predictions.

Contribution

The study provides the first quantitative experimental verification of the phase-charge duality in Josephson junctions considering environmental fluctuations.

Findings

Observation of Coulomb blockade and Bloch oscillations.

Experimental confirmation of phase-charge duality.

Quantitative agreement with theoretical models including temperature effects.

Abstract

We have measured the current-voltage characteristics of a single Josephson junction placed in a high impedance environment. The transfer of Cooper pairs through the junction is governed by overdamped quasicharge dynamics, leading to Coulomb blockade and Bloch oscillations. Exact duality exists to the standard overdamped phase dynamics of a Josephson junction, resulting in a dual shape of the current-voltage characteristic, with current and voltage changing roles. We demonstrate this duality with experiments which allow for a quantitative comparison with a theory that includes the effect of fluctuations due to finite temperature of the electromagnetic environment.