Kerr microscopy real-time imaging of the magnetization reversal process in kagome artificial spin ice

Abstract

The magnetization reversal process in an interconnected kagome artificial spin ice has been investigated using high-resolution Kerr microscopy. The magnetization switching with two-dimensional system-size avalanches has been directly imaged for the applied field parallel to one of the sublattice branches, suggesting very low disorder in our sample. The discrete one-dimensional Dirac-string-like magnetization reversal is found for the field with a certain angle. The real-time imaging under the field suggests that the reversal of the third bars next to the reversed Dirac string can mediate the reversal of the neighboring Dirac string. The observed reversal behaviors can be understood by the ice rule, consistent with the micromagnetic simulation results. Our studies demonstrate that Kerr microscopy can be applied to study the magnetization reversal process in artificial spin ice structures in real space and real time under an external magnetic field.