Electromagnetic-field-induced decay of currents in thin-film superconducting rings with photons emission

TL;DR

This paper investigates how coherent microwave irradiation causes quantized decay of supercurrents in thin-film superconducting rings, leading to photon emission and flux quantum destruction, with detailed probability and angular distribution analyses.

Contribution

It introduces a model for microwave-induced supercurrent decay in superconducting rings, including photon emission probabilities and angular distributions, highlighting the quantum nature of the decay process.

Findings

Supercurrents decay discretely with photon emission.

Decay probabilities depend on ring size and fluxoid number.

Photon emission angular distributions are characterized.

Abstract

It is shown that currents in thin-film superconducting rings irradiated by coherent microwave fields, can discretely decay with photons emission. These quantized jumps of the supercurrent correspond to destruction one or several magnetic flux quanta trapped in the ring. The ring thickness should be less than the skin-depth of the low-frequency field. The probability of the microwave field-induced single-photon decay of the supercurrent states in these rings is obtained. The angle distributions of the photons emitted by superconducting rings, and the current state lifetimes, depending on the ring sizes and the fluxoid numbers in the initial states, are studied.