Magnetic dipole induced guided vortex motion

TL;DR

This study demonstrates how magnetic dipoles in a hybrid superconductor/ferromagnet system can control and guide vortex motion, with the ability to re-route or suppress flux flow via magnetic state manipulation.

Contribution

It introduces a method to control vortex guidance in superconductors using magnetic dipole arrays, enabling re-routing or suppression of vortex motion.

Findings

Magnetic dipoles create anisotropic pinning landscapes.

Vortex motion can be guided along specific lattice axes.

Magnetic states can re-route or suppress vortex flow.

Abstract

We present evidence of magnetically controlled guided vortex motion in a hybrid superconductor/ferromagnet nanosystem consisting of an Al film on top of a square array of permalloy square rings. When the rings are magnetized with an in-plane external field H, an array of point-like dipoles with moments antiparallel to H, is formed. The resulting magnetic template generates a strongly anisotropic pinning potential landscape for vortices in the superconducting layer. Transport measurements show that this anisotropy is able to confine the flux motion along the high symmetry axes of the square lattice of dipoles. This guided vortex motion can be either re-routed by 90 degrees by simply changing the dipole orientation or even strongly suppressed by inducing a flux-closure magnetic state with very low stray fields in the rings.