Giant paramagnetic Meissner effect in multiband superconductors.

R M Da Silva,J Albino Aguiar,A A Shanenko,F M Peeters,M V Milošević

doi:10.1038/srep12695

R M Da Silva, J Albino Aguiar + Show 3 more

Open Access

https://doi.org/10.1038/srep12695

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Abstract

Superconductors, ideally diamagnetic when in the Meissner state, can also exhibit paramagnetic behavior due to trapped magnetic flux. In the absence of pinning such paramagnetic response is weak, and ceases with increasing sample thickness. Here we show that in multiband superconductors paramagnetic response can be observed even in slab geometries, and can be far larger than any previous estimate - even multiply larger than the diamagnetic Meissner response for the same applied magnetic field. We link the appearance of this giant paramagnetic response to the broad crossover between conventional Type-I and Type-II superconductors, where Abrikosov vortices interact non-monotonically and multibody effects become important, causing unique flux configurations and their locking in the presence of surfaces.

Highlights

The diamagnetic Meissner effect is one of the hallmarks of superconductivity, where applied magnetic field is ideally screened out of the superconductor when cooled below the critical temperature Tc
The calculations are performed within the two-component Ginzburg-Landau (TCGL) theory
What is the underlying mechanism for the giant paramagnetic response? In simple terms, it is the facilitated trapping of magnetic flux in the crossover domain between Type-I and Type-II superconductivity, since vortices attract in the entire range of parameters where GPR is observed

Summary

Introduction

The diamagnetic Meissner effect is one of the hallmarks of superconductivity, where applied magnetic field is ideally screened out of the superconductor when cooled below the critical temperature Tc. It is clear that non-monotonic vortex interaction and other interplay effects between condensates in multiband superconductors are bound to affect the interactions of trapped magnetic flux with the sample boundaries, and can lead to novel manifestations of the paramagnetic Meissner response.

Results

Conclusion