A Superconducting Reversible Rectifier That Controls the Motion of Magnetic Flux Quanta

TLDR

The study develops and theoretically models a ratchet system that controls vortex motion by considering particle interactions. A niobium superconducting film with nanoscale triangular pinning potentials was fabricated, and the vortex flow reversal was attributed to interactions between vortices trapped on magnetic nanostructures and interstitial vortices, with the system modeled theoretically. Rectification of vortex motion is achieved through asymmetric magnetic pinning centers, and the polarity and magnitude of the rectified flow can be tuned by adjusting the applied magnetic field and input current.

Abstract

We fabricated a device that controls the motion of flux quanta in a niobium superconducting film grown on an array of nanoscale triangular pinning potentials. The controllable rectification of the vortex motion is due to the asymmetry of the fabricated magnetic pinning centers. The reversal in the direction of the vortex flow is explained by the interaction between the vortices trapped on the magnetic nanostructures and the interstitial vortices. The applied magnetic field and input current strength can tune both the polarity and magnitude of the rectified vortex flow. Our ratchet system is explained and modeled theoretically, taking the interactions between particles into consideration.