Realization of Artificial Ice Systems for Magnetic Vortices in a Superconducting MoGe Thin-film with Patterned Nanostructures

TL;DR

This paper demonstrates the creation of an artificial ice system for magnetic vortices in a superconducting MoGe thin film with patterned nanostructures, revealing novel vortex arrangements and enhanced critical currents at specific magnetic fields.

Contribution

It introduces the first experimental realization of an artificial ice system for vortices in superconductors using patterned nanostructures, supported by numerical simulations.

Findings

Observation of a pronounced fractional matching effect.

Critical current exceeds zero-field value at half matching field.

Numerical confirmation of a square vortex ice configuration.

Abstract

We report an anomalous matching effect in MoGe thin films containing pairs of circular holes arranged in such a way that four of those pairs meet at each vertex point of a square lattice. A remarkably pronounced fractional matching was observed in the magnetic field dependences of both the resistance and the critical current. At the half matching field the critical current can be even higher than that at zero field. This has never been observed before for vortices in superconductors with pinning arrays. Numerical simulations within the nonlinear Ginzburg-Landau theory reveal a square vortex ice configuration in the ground state at the half matching field and demonstrate similar characteristic features in the field dependence of the critical current, confirming the experimental realization of an artificial ice system for vortices for the first time.