Hybridized Frequency Combs in Multimode Cavity Electromechanical System.

The cavity electromechanical devices with radiation-pressure interaction induced Kerr-like nonlinearity are promising candidates to generate microwave frequency combs. We construct a silicon-nitride membrane based superconducting cavity electromechanical device and study two mechanical modes synergistic frequency combs. Around the threshold of intracavity field instability, we first show independent frequency combs with tooth spacing equal to each mechanical mode frequency.