Noise matching and sensitivity improvement in aluminum nitride nanoelectromechanical resonators via parametric amplification

Abstract

Parametric amplification of ultrasmall signals from electromechanical transducers directly in the mechanical domain, prior to electrical readout, is an intriguing challenge and is important for both scientific measurements and technologies utilizing micro/nanoelectromechanical systems (MEMS/NEMS). Here, we report on parametric amplification of aluminum nitride (AlN) multimode NEMS resonators (with broad intrinsic dynamic ranges up to 90 dB) for enabling detection of their thermomechanical resonances in both optical and electrical readout schemes simultaneously. The experiments demonstrate that, upon parametric pumping, the electrically transduced thermomechanical motions experience significant amplification, surpassing the extrinsic electronic noise level, while still below the parametric pumping threshold. We achieve noise matching that enables room temperature force sensitivity of 0.46 fN/Hz1/2. We observe high parametric gain up to 650, accompanied by a strong boost (over 3.5×) in the effective quality factor (Qeff, from 9000 to 32 000). These findings underscore the utilities of parametric amplification in noise matching and improving force sensitivity for NEMS transducers and their emerging applications.