Abnormal magnetoresistance behavior in Nb thin film with rectangular antidot lattice

TL;DR

This paper reports an unusual magnetoresistance reversal in Nb thin films with rectangular antidot arrays, attributed to a strong vortex caging effect that traps interstitial vortices, especially at low temperatures or current densities.

Contribution

It reveals a novel abnormal magnetoresistance behavior in superconducting Nb films with rectangular antidots, linked to vortex caging effects not previously documented.

Findings

Magnetoresistance reverses at low temperature or current density.

Strong vortex caging traps interstitial vortices.

Abnormal behavior linked to vortex dynamics in antidot lattices.

Abstract

Abnormal magnetoresistance behavior is found in superconducting Nb films perforated with rectangular arrays of antidots (holes). Generally magnetoresistance were always found to increase with increasing magnetic field. Here we observed a reversal of this behavior for particular in low temperature or current density. This phenomenon is due to a strong 'caging effect' which interstitial vortices are strongly trapped among pinned multivortices.