Bistability of Cavity Magnonics System with Magnon Kerr Effect

Abstract

In this study a comprehensive theory is developed for a hybrid cavity magnonics system consisting of a microwave cavity strongly coupled to spin excitations or magnons in a single-crystal yttrium iron garnet (YIG) sample with the magnons exhibiting nonlinear Kerr effect caused by magnetocrystalline anisotropy in YIG. The system dynamics is analysed in Hamilton Langevin formulation and it is shown that the magnon frequency shift due to Kerr nonlinearity is bistable with a upper and a lower branch of cavity magnon polaritons (CMP). Further by analytically and graphically studying different conditions imposed on the bistability equation it is demonstrated that the bistability is controllable by tuning the system parameters involved.