Giant Shapiro Resonances in a Flux Driven Josephson Junction Necklace

TL;DR

This paper investigates the dynamic response of a ring of Josephson junctions under periodic flux, revealing giant Shapiro resonances that depend on phase slips, system size, inductance, and drive frequency, with potential experimental observability.

Contribution

It introduces the discovery of subharmonic giant Shapiro voltage resonances in Josephson junction rings, considering screening effects and providing experimental parameter estimates.

Findings

Identification of subharmonic giant Shapiro voltage resonances.

Dependence of resonances on phase slips, system size, and drive frequency.

Estimation of experimental conditions for observing these phenomena.

Abstract

We present a detailed study of the dynamic response of a ring of $N$ equally spaced Josephson junctions to a time-periodic external flux, including screening current effects. The dynamics are described by the resistively shunted Josephson junction model, appropriate for proximity effect junctions, and we include Faraday's law for the flux. We find that the time-averaged $I-V$ characteristics show novel {\em subharmonic giant Shapiro voltage resonances}, which strongly depend on having phase slips or not, on $N$, on the inductance and on the external drive frequency. We include an estimate of the possible experimental parameters needed to observe these quantized voltage spikes.