Directional vortex motion guided by artificially induced mesoscopic potentials

TL;DR

This paper demonstrates how artificially created mesoscopic pinning landscapes in Nb films can control vortex motion direction, revealing lock-in effects and angular dependencies in vortex dynamics.

Contribution

It introduces a method to guide vortex motion using rectangular Ni dot arrays, showing significant directional locking effects in superconducting films.

Findings

Vortex motion can be directed up to 85° away from the Lorentz force.

Periodic pinning arrays induce vortex channeling along specific directions.

Angular dependence of dissipation varies with magnetic field strength.

Abstract

Rectangular pinning arrays of Ni dots define a potential landscape for vortex motion in Nb films. Magnetotransport experiments in which two in-plane orthogonal electrical currents are injected simultaneously allow selecting the direction and magnitude of the Lorentz force on the vortex-lattice, thus providing the angular dependence of the vortex motion. The background dissipation depends on angle at low magnetic fields, which is progressively smeared out with increasing field. The periodic potential locks in the vortex motion along channeling directions. Because of this, vortex-lattice direction of motion is up to 85o away from the applied Lorentz force direction.