Spin-wave dynamics and symmetry breaking in an artificial spin ice

TL;DR

This paper explores the complex spin-wave behavior and symmetry breaking in artificial spin ices, revealing how local structural asymmetries influence magnetic excitations and their potential for reconfigurable magnonic applications.

Contribution

It provides new insights into the magnetization dynamics and mode evolution in anisotropic artificial spin ices with broken symmetry, extending understanding beyond traditional geometries.

Findings

Rich spin-wave spectrum observed

Symmetry breaking influences mode profiles

Long-range interactions affect mode spectra

Abstract

Artificial spin ices are periodic arrangements of interacting nanomagnets successfully used to investigate emergent phenomena in the presence of geometric frustration. Recently, it has been shown that artificial spin ices can be used as building blocks for creating functional materials, such as magnonic crystals, and support a large number of programmable magnetic states. We investigate the magnetization dynamics in a system exhibiting anisotropic magnetostatic interactions owing to locally broken structural inversion symmetry. We find a rich spin-wave spectrum and investigate its evolution in an external magnetic field. We determine the evolution of individual modes, from building blocks up to larger arrays, highlighting the role of symmetry breaking in defining the mode profiles. Moreover, we demonstrate that the mode spectra exhibit signatures of long-range interactions in the system. These results contribute to the understanding of magnetization dynamics in spin ices beyond the kagome and square ice geometries and are relevant for the realization of reconfigurable magnonic crystals based on spin ices.