Parametrically pumped ultrahigh Q electromechanical resonator

The spectral purity of an electromechanical resonance (quality factor Q) can be enhanced by more than one order of magnitude to similar to 2.5 x 10(6) by parametrically exciting the fundamental mode via double frequency modulations to the spring constant mediated by the piezoelectric effect. We theoretically demonstrate that this Q enhancement is an intrinsic property of the parametric resonator by solving the equation of motion for this system. The Q enhancement demonstrated here results in smaller perturbations in the resonance (similar to 0.05 Hz) becoming visible which enables the charge sensitivity of the electromechanical oscillator to improve by a factor equal to the Q enhancement. (C) 2008 American Institute of Physics.