Non-linear control of magnon-polariton hybridisation

マグノンポラリトン混成の非線形制御

山本 慧   ; 紅林 秀和*

Yamamoto, Kei; Kurebayashi, Hidekazu*

Motivated by the importance of non-linearity in general in quantum manipulation of cavity photons, we study the non-linear spin wave instability when a magnetic film is strongly coupled to a microwave resonator mode. We show both experimentally and theoretically that when the input driving power exceeds a certain threshold, the first-order Suhl instability for the spin waves manifests itself as an apparent closure of the anti-crossing gap in the microwave reflection spectrum of the coupled system. We identify its mechanism to be the blocking of hybridisation between the Kittel mode magnon and the resonator photon by a coherent back reaction from the unstable magnon pair.