Identification and time-resolved study of YIG spin wave modes in a MW cavity in strong coupling regime

TL;DR

This paper studies the strong coupling between YIG spin wave modes and microwave cavity modes, demonstrating coherent energy exchange and introducing a new method for identifying magnetostatic modes to advance hybrid quantum systems.

Contribution

It presents a novel approach for identifying magnetostatic modes in YIG spheres within a microwave cavity, enabling better analysis of hybrid magnon-photon systems.

Findings

Observation of anti-crossing features indicating strong coupling.

Evidence of Rabi oscillations showing coherent energy exchange.

Introduction of a new functional variable for easier mode identification.

Abstract

Recently, the hybridization of microwave-frequency cavity modes with collective spin excitations attracted large interest for the implementation of quantum computation protocols, which exploit the transfer of information among these two physical systems. Here, we investigate the interaction among the magnetization precession modes of a small YIG sphere and the MW electromagnetic modes, resonating in a tridimensional aluminum cavity. In the strong coupling regime, anti-crossing features were observed in correspondence of various magnetostatic modes, which were excited in a magnetically saturated sample. Time-resolved studies show evidence of Rabi oscillations, demonstrating coherent exchange of energy among photons and magnons modes. To facilitate the analysis of the standing spin-wave patterns, we propose here a new procedure, based on the introduction of a novel functional variable. The resulting easier identification of magnetostatic modes can be exploited to investigate, control and compare many-levels hybrid systems in cavity- and opto-magnonics research.