Observation of mode splitting in artificial spin ice

TL;DR

This study investigates how the magnetization dynamics in artificial spin ice are affected by the in-plane magnetic field angle, revealing controllable mode splitting and localization through experimental and simulation methods.

Contribution

It demonstrates the field-angle dependence of mode splitting in artificial spin ice and shows how external fields can control mode localization and dynamics.

Findings

Mode splitting depends on magnetic field angle and magnitude.

Split modes are localized in different regions of the lattice.

External field tuning can disentangle modes with different spatial profiles.

Abstract

We report the dependence of the magnetization dynamics in a square artificial spin-ice lattice on the in-plane magnetic field angle. Using two complementary measurement techniques - broadband ferromagnetic resonance and micro-focused Brillouin light scattering spectroscopy - we systematically study the evolution of the lattice dynamics, both for a coherent radiofrequency excitation and an incoherent thermal excitation of spin dynamics. We observe a splitting of modes facilitated by inter-element interactions that can be controlled by the external field angle and magnitude. Detailed time-dependent micromagnetic simulations reveal that the split modes are localized in different regions of the square network. This observation suggests that it is possible to disentangle modes with different spatial profiles by tuning the external field configuration.