Entanglement of magnon excitations with antiferromagnetic coupling

Quantum entanglement as a major non-classical resource naturally comes about in any quantum technology protocol, including quantum magnonics. We discuss how an antiferromagnetic coupling leads to experimentally detectable bipartite continuous variable entanglement between two ferromagnetic magnon modes [1, 2]. We then present a clear relation between this entanglement and Einstein, Podolsky, and Rosen non-locality. Based on this relation a practical experimental setup for detecting the EPR function of the ground state as well as the magnon-magnon entanglement will be discussed. The setting relies on magnon-photon interaction in a microwave cavity [2].

[1] V. Azimi-Mousolou, et al., Hierarchy of magnon mode entanglement in antiferromagnets, Phys. Rev. B 102, 224418 (2020).

[2] V. Azimi-Mousolou, et al., Magnon-magnon entanglement and its detection in a microwave cavity, (2021). arXiv:2106.06862