Hysteretic jumps in the response of layered superconductors to electromagnetic fields

TL;DR

This paper predicts hysteretic jumps in the surface reactance of layered superconductors under electromagnetic fields, especially near the Josephson plasma frequency, revealing a novel nonlinear response observable in thin slabs.

Contribution

It introduces a theoretical prediction of hysteretic behavior in layered superconductors' electromagnetic response using coupled sine-Gordon equations.

Findings

Hysteretic jumps occur in surface reactance near Josephson plasma frequency.

Hysteresis depends on incident wave amplitude and frequency.

Conditions for hysteresis are derived mathematically.

Abstract

We consider here a layered superconductor subject to an externally applied moderately-strong electromagnetic field. We predict hysteretic jumps in the dependence of the surface reactance of the superconductor on the amplitude of the incident electromagnetic wave. This very unusual nonlinear phenomenon can be observed in thin superconducting slabs at not very strong ac amplitudes, if the frequency of the irradiating field is close to the Josephson plasma frequency. Using the set of coupled sine-Gordon equations, we derive the expression for the phase shift of the reflected wave and obtain the conditions for the appearance of hysteresis.