Controllable magnon-induced transparency in a ferromagnetic material via cross- and self-Kerr effects

Abstract

Nonlinear interactions between optical fields and magnetic modes in cavity magnonics constitute a rich source of various nontrivial effects in optics and quantum information processing. In cavity magnonics, biased ferromagnetic material exhibits both magnetostatic and Kittle modes due to field inhomogeneity. Here, we propose a scheme for the investigation of probe field transmission profiles in cavity magnonic systems composed of a microwave cavity and a ferromagnetic material (yttrium iron garnet sphere). We report single-to-double magnon-induced transparency (MIT) dips and a sharp magnon-induced absorption peak, and demonstrate how nonlinear cross- and self-Kerr interactions can significantly enhance or suppress these phenomena. It is observed that the splitting of the MIT window occurs when we incorporate magnon–magnon mode coupling, which helps to introduce a degree of freedom to light–matter interaction problems. Moreover, we investigate the propagation of group delay in the vicinity of transparency and demonstrate how a sharp dip allows the realization of slow light for a longer period of time. We found that both the cavity–Kittle and magnon–magnon mode coupling parameters influence the propagation of group delay, which demonstrates how subluminal-to-superluminal (and vice versa) propagation phenomena may occur and transform. These findings could pave the way for future research into nonlinear effects with novel applications in cavity magnonics devices, which might be exploited for several applications such as quantum computing devices and quantum memories.