Emergent Magnetic Monopole and Dipole Screening by Proximity Effect With Noble Metal

Abstract

In this work we present emergent screening of magnetic monopole and dipole by the presence of 20nm aluminum cover layer onsquare artificial spin ice (ASI) systems. Our results were obtained in base of magnetic atomic force measurements, performedafter external magnetic field steps application. We show that the evolution of magnetization and monopole population is affectedby the aluminum presence and attribute that phenomena to the proximity effect, which is responsible for the magnetizationvanish of the first atomic layers at the ferromagnetic interface. Using experimental values to estimate the decrease in thenanomagnetic dipole value used in an emergent excitation model and in the switching field distribution heterogeneity usedin simulations, we observe a very good agreement among experimental and simulation results. The presented emergentscreening could be used in new ASI geometries for thermodynamic activation or proposition of devices with selective magneticmonopole mobility.