Spin Optodynamics in Magnetic Solids

Coherent couplings between cavity photons and spin ensembles, such as cold atoms [1] and nanomagnets [2], have been studied theoretically before. By virtue of magneto-optic interactions, we propose here to use a photonic cavity made of magnetic crystal to study the intrinsic coupling rate ($g_0$) that describes the effect of a single photon on the cavity. Cavity bistability due to multistatic magnetization is identified, and with clever choosing of driving fields, one can realize coherent amplification/damping of spin-wave amplitudes, which is superior than the incoherent methods, such as the one using spin transfer torque. Our theory has great potential in developing all optical control of magnonics.\\[4pt] [1] N. Brahms and D. M. Stamper-Kurn, Phys. Rev. A {\bf 82}, 041804 (2010).\\[0pt] [2] \"{O} O. Soykal and M. E. Flatt\'e, Phys. Rev. Lett. {\bf 104}, 077202 (2010).