Multimode coupling and nonlinear dynamics in coupled double-drum resonators
Résumé
Parametrically coupled micro- and nano-electromechanical resonators serve as ideal model systems for the study of coherent multimode energy transfer and conversion, offering diverse interaction mechanisms and flexible control of mode coupling [1-3]. In this work, we present experimental and theoretical studies on the unconventional thermal noise squeezing, control of multimode coupling, and nonlinear dynamics in double-drum resonator systems. The results reveal the rich dynamics of coupled double-drum resonators and present potential for advancing phononic applications that involve a large number of coupled mechanical modes. The double-drum resonator used in this study consists of a silicon nitride drum and an aluminium drum configured as parallel vibrating plates coupled by electrostatic forces [1-2]. First, we present the squeezing of the thermal noise carried by both drum resonators by simultaneously pumping the silicon nitride resonator at its blue and red sidebands with frequency detuning around the aluminium drum resonance frequency. The unconventional squeezing phenomenon was observed, beyond the standard 2Ω parametric pumping with the 3dB limit. These observations are modelled by the parametrically coupled equations of motion in the linear regime and can be understood by considering the destructive interference produced by the two pump tones in this parametrically coupled system.