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arXiv · 2503.22882

Cavity-assisted magnetization switching in a quantum spin-phonon chain

Mohsen Yarmohammadi·Peter M. Oppeneer·James K. Freericks
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Abstract

We propose a N\'eel magnetization switching mechanism in a hybrid magnon-phonon optical cavity system. A terahertz-pumped single-mode cavity photon couples to a spin-phonon chain, while the system dissipates energy via different baths. Our mean-field analysis reveals that the photon induces magnetization switching by generating strongly entangled magnon pairs with opposite momenta -- a feature weakly present in the cavity-free system. This switching occurs only at specific drive frequencies, namely at low magnon energies and near the upper edge (perpendicular modes) of the two-magnon band. Our results underscore the roles of laser fluence, damping, and photon loss in modulating the switching process, offering a promising route for cavity-assisted magnetization control in opto-spintronics.

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Mohsen Yarmohammadi, Peter M. Oppeneer, James K. Freericks. 2025-03-28. Cavity-assisted magnetization switching in a quantum spin-phonon chain. https://doi.org/10.1103/88tw-h78r

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