Experimental Evidence for Giant Vortex States in a Mesoscopic Superconducting Disk

TL;DR

This study provides experimental evidence for giant vortex states in mesoscopic superconducting disks, distinguishing them from multivortex states and observing vortex rearrangements under magnetic fields, supported by numerical Ginzburg-Landau modeling.

Contribution

First experimental distinction between giant vortex and multivortex states in mesoscopic superconductors using tunnel junction measurements.

Findings

Identification of giant vortex states

Magnetic field induced vortex rearrangements

Agreement with Ginzburg-Landau theory simulations

Abstract

Response of a mesoscopic superconducting disk to perpendicular magnetic fields is studied by using the multiple-small-tunnel-junction method, in which transport properties of several small tunnel junctions attached to the disk are measured simultaneously. This allows us for the first experimental distinction between the giant vortex states and multivortex states. Moreover, we experimentally find magnetic field induced rearrangement and combination of vortices. The experimental results are well reproduced in numerical results based on the nonlinear Ginzburg-Landau theory.