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arXiv · 2404.13190

Anomalous Long-Distance Coherence in Critically-Driven Cavity Magnonics

Ying Yang·Jiguang Yao·Yang Xiao·Pak-Tik Fong·Hoi-Kwan Lau·C. -M. Hu
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Abstract

Developing quantum networks necessitates coherently connecting distant systems via remote strong coupling. Here, we demonstrate long-distance coherence in cavity magnonics operating in the linear regime. By locally setting the cavity near critical coupling with travelling photons, non-local magnon-photon coherence is established via strong coupling over a 2-meter distance. We observe two anomalies in this long-distance coherence: first, the coupling strength oscillates twice the period of conventional photon-mediated couplings; second, clear mode splitting is observed within the cavity linewidth. Both effects cannot be explained by conventional coupled-mode theory, which reveal the tip of an iceberg of photon-mediated coupling in systems under critical driving. Our work shows the potential of using critical phenomena for harnessing long-distance coherence in distributed systems.

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Ying Yang, Jiguang Yao, Yang Xiao, Pak-Tik Fong, Hoi-Kwan Lau, C. -M. Hu. 2024-04-19. Anomalous Long-Distance Coherence in Critically-Driven Cavity Magnonics. https://doi.org/10.1103/physrevlett.132.206902

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