Magnetic-field-direction-controlled slow light and second-order sidebands in a cavity-magnon optomechanical system

We theoretically study how the magnetic field direction controls both the transmission rate and the group delay of the signal, as well as the second-order sideband process in a hybrid cavity-magnon optomechanical system. By tuning the direction of the bias magnetic field, either a positive or negative magnon Kerr coefficient can be achieved, leading to a corresponding shift in the magnon frequency. As a result, the transmission rate can be significantly modified, resulting in a Fano-like transparency spectrum governed by the magnetic field direction, along with a slow-to-fast light switch also influenced by that direction. Moreover, we study the impact of magnetic field direction on the second-order sidebands, revealing that the enhancement of the second-order sideband effect is dependent on this direction. These findings pave the way to engineering magnon Kerr nonlinearity-assisted optomechanical devices for applications in signal propagation and storage.