We present a theoretical approach to use ferro- or ferrimagnetic nanoparticles as microwave nanomagnonic cavities to concentrate microwave magnetic fields into deeply subwavelength volumes ∼10−13 mm3. We show that the field in such nanocavities can efficiently couple to isolated spin emitters (spin qubits) positioned close to the nanoparticle surface reaching the single magnon-spin strong-coupling regime and mediate efficient long-range quantum state transfer between isolated spin emitters. Nanomagnonic cavities thus pave the way towards magnon-based quantum networks and magnon-mediated quantum gates.
@article{arxiv.2007.11595,
title = {Nanomagnonic cavities for strong spin-magnon coupling},
author = {Tomáš Neuman and Derek S. Wang and Prineha Narang},
journal= {arXiv preprint arXiv:2007.11595},
year = {2021}
}