Tunable Entangling and Steering of Ferrimagnetic Magnons Via an OptoMagnoMechanical Ring

Abstract

ABSTRACT Recently, magnomechanical systems have emerged as promising platforms for quantum technologies, exploiting magnon–photon–phonon interactions to store high‐fidelity quantum information. In this paper, we propose a novel scheme to entangle two spatially separated ferrimagnetic YIG crystals by injecting a laser field into an optomagnonic ring cavity. The proposed optomagnomechanical configuration utilizes the coupling between magnetostriction‐induced mechanical displacements and the optical cavity via radiation pressure. Magnons, collective spin excitations in macroscopic ferrimagnets, are directly driven by an electromagnetic field. We demonstrate the generation of a robust macroscopic entangled state via exciting the optical cavity with a red‐detuned laser field and the YIG crystals with blue‐detuned microwave fields. Our analysis reveals that magnon entanglement vanishes for identical magnomechanical couplings and remains robust against thermal fluctuations. Moreover, the quantum steering can be tuned directionally by the asymmetry of the magnomechanical coupling, allowing for a selective control of the optomagnetic quantum correlations. The entangled magnon modes in two ferrimagnetic crystals represent genuine macroscopic quantum states with potential applications in the study of macroscopic quantum mechanics and quantum information processing based on magnonics. Our model is based on experimentally accessible parameters, providing a feasible route to quantum technologies.