Symmetry effects on the static and dynamic properties of coupled magnetic oscillators

TL;DR

This paper investigates how symmetry influences the resonance spectra of coupled magnetic oscillators, using experimental characterization and group theory modeling to understand symmetry-breaking effects in synthetic antiferromagnets.

Contribution

It introduces a novel experimental approach to tune magnetization in coupled oscillators and applies group theory to model their resonance spectra, bridging classical and quantum symmetry concepts.

Findings

Symmetry-breaking induces anti-crossings in resonance spectra.

Independent tuning of magnetization reveals symmetry effects.

Group theory effectively models the resonance features.

Abstract

The effect of symmetry on the resonance spectra of antiferromagnetically coupled oscillators has attracted new interest with the discovery of symmetry-breaking induced anti-crossings. Here, we experimentally characterise the resonance spectrum of a synthetic antiferromagnet Pt/CoFeB/Ru/CoFeB/Pt, where we are able to independently tune the effective magnetisation of the two coupled magnets. To model our results we apply the mathematical methods of group theory to the solutions of the Landau Lifshitz Gilbert equation. This general approach, usually applied to quantum mechanical systems, allows us to identify the main features of the resonance spectrum in terms of symmetry breaking and to make a direct comparison with crystal antiferromagnets.