Magnetic invisibility of the magnetically coated type-II superconductor in partially penetrated state

J Peña-Roche,A Badía-Majós,Y A Genenko

doi:10.1063/1.4961672

Abstract

The magnetic behavior of a cylindrical paramagnet/superconductor heterostructure has been studied by numerical simulations. Relying on the variational statement of the critical state model, our results show that magnetic invisibility is compatible with the partial penetration regime in the superconductor. This result accomplishes previous analytic studies that proved a possible perfect undetectability for the full penetration of magnetic flux. For a given geometry, invisibility may be realized only at a certain magnitude of the applied field. Such value decreases with increasing permeability of the magnetic sheath and eventually collapses to zero. This establishes a condition for obtaining realizable invisibility that extends previous expectations relying either on the full penetration ansatz or on perfect diamagnetism.

Highlights

We consider the response of a long superconducting wire, covered by a concentric layer of paramagnetic material
Relying on the variational statement of the critical state model, our results show that magnetic invisibility is compatible with the partial penetration regime in the superconductor
The system is exposed to a uniform external magnetic field H0 perpendicular to its axis (z-axis in what follows)

Summary

Introduction

We consider the response of a long superconducting wire (circular cross section), covered by a concentric layer of paramagnetic material. Relying on the variational statement of the critical state model, our results show that magnetic invisibility is compatible with the partial penetration regime in the superconductor.

Results

Conclusion