Field-free superconducting diode in a magnetically nanostructured superconductor

TL;DR

This paper demonstrates a magnetic nanostructure-enabled superconducting diode effect that operates without external magnetic fields, using vortex-antivortex dynamics to achieve diode-like behavior in a thin superconducting film.

Contribution

It introduces a novel magnetic nanostructuring approach to realize a field-free superconducting diode based on vortex-antivortex dynamics.

Findings

Superconducting diode effect observed in nanostructured films.

Diode behavior depends on vortex-antivortex nucleation and annihilation.

Simulations identify geometric and parametric conditions for realization.

Abstract

A strong superconducting diode effect (SDE) is revealed in a thin superconducting film periodically nanostructured with magnetic dots. The SDE is caused by the current-activated dissipation mitigated by vortex-antivortex pairs (VAPs), which periodically nucleate under the dots, move and annihilate in the superconductor - eventually driving the system to the high-resistive state. Inversing the polarity of the applied current destimulates the nucleation of VAPs, the system remains superconducting up to far larger currents, leading to the pronounced diodic response. Our dissipative Ginzburg-Landau simulations detail the involved processes, and provide reliable geometric and parametric ranges for the experimental realization of such a non-volatile superconducting diode, which operates in absence of any applied magnetic field while being fluxonic by design.