Modeling nonlinearity and hysteresis due to critical-state flux penetration in hard superconductors

TL;DR

This paper presents a numerical model for the nonlinear surface impedance of superconducting strips, accounting for flux penetration and critical states, aiding in the design of microwave circuits.

Contribution

It introduces a first-principles numerical approach to model flux penetration and hysteresis effects in superconductors, aligning with analytic results in relevant limits.

Findings

Numerical calculations match analytic results in the appropriate limit.

The model captures nonlinear surface impedance due to flux penetration.

Useful for designing superconducting microwave circuits.

Abstract

The nonlinear surface impedance of a thin superconducting strip carrying a microwave current has been calculated numerically from first principles based upon flux penetration due to a current-induced critical state. The calculations approach analytic results in the appropriate limit. The technique is useful for design of passive superconducting microwave circuits.