Emergent magnetic monopole and dipole screening by proximity effect with noble metal

TL;DR

This study demonstrates that a 20nm aluminum layer can induce emergent screening of magnetic monopoles and dipoles in artificial spin ice, affecting magnetization and monopole populations through the proximity effect, with implications for device design.

Contribution

It reveals how a thin aluminum layer causes emergent magnetic screening in artificial spin ice, combining experimental measurements and simulations to understand the proximity effect.

Findings

Aluminum layer reduces magnetization of atomic layers at the interface.

Good agreement between experimental data and simulation models.

Potential applications in designing devices with controlled magnetic monopole mobility.

Abstract

In this letter we present emergent screening of magnetic monopole and dipole by the presence of 20nm aluminum cover layer. Our results were obtained in base of magnetic atomic force measurements, performed after external magnetic field steps application. We show that the evolution of magnetization and monopole population is affected by the aluminum presence and attribute that phenomena to the proximity effect, which is responsible for the magnetization vanish of the firstatomic layers at the interface. Using experimental values to estimate the decrease in the nano-magnetic dipole value used in an emergent excitation model and in the switching field distribution heterogeneity used in simulations, we observe a very good agreement among experimental and simulation results. The presented emergent screening could be used in new ASI geometries for thermodynamic activation or proposition of devices with selective magnetic monopole mobility.