Optical quadrature squeezing via the Faraday effect in cavity optomagnonics

Coherently manipulating quadrature squeezing is highly desired for precision measurement applications, but remains challenging due to an inaccessible standard quantum limit in most micro- and nanostructures. Here, we propose an efficient scheme to generate quadrature squeezing in a cavity optomagnonical system. Taking the magnon–photon interaction induced by the Faraday effect into consideration, we report that a strong quadrature squeezing can be achieved in the effective resonant cavity modes that obey the mode-splitting theory of Bogoliubov transformation. Using experimentally achievable parameters, we illustrate that increasing the magnon–photon coupling strength or input field intensity contributes to improving both the output spectral intensity and the amount of squeezing of the spectra, where perfect squeezing is only located at the position of the single resonant cavity mode. Interestingly enough, the nearly perfect quadrature squeezing at the double frequencies of the effective resonant cavity modes can be achieved by adjusting the input field frequency and intensity.