Reconfigurable magnonic mode-hybridisation and spectral control in a bicomponent artificial spin ice

TL;DR

This paper demonstrates a method to reconfigure and control magnonic spectra in artificial spin ice by modifying array geometry and microstate, enabling tunable mode hybridization and spectral features.

Contribution

The study introduces a scalable approach to access diverse microstates in artificial spin ice with tunable magnonic properties through geometric modifications and global-field protocols.

Findings

Microstate-dependent magnon spectra observed.

Dynamic coupling strength up to 0.15 GHz.

Active mode frequency shifting and gap control achieved.

Abstract

Strongly-interacting nanomagnetic arrays are finding increasing use as model host systems for reconfigurable magnonics. The strong inter-element coupling allows for stark spectral differences across a broad microstate space due to shifts in the dipolar field landscape. While these systems have yielded impressive initial results, developing rapid, scaleable means to access abroad range of spectrally-distinct microstates is an open research problem.We present a scheme whereby square artificial spin ice is modified by widening a 'staircase' subset of bars relative to the rest of the array, allowing preparation of any ordered vertex state via simple global-field protocols. Available microstates range from the system ground-state to high-energy 'monopole' states, with rich and distinct microstate-specific magnon spectra observed. Microstate-dependent mode-hybridisation and anticrossings are observed at both remanence and in-field with dynamic coupling strength tunable via microstate-selection. Experimental coupling strengths are found up to g / 2$\pi$ = 0.15 GHz. Microstate control allows fine mode-frequency shifting, gap creation and closing, and active mode number selection.