High Q nanomechanical systems

Doubly-clamped pre-stressed silicon nitride string resonators excel as high Q nanomechanical systems enabling room temperature quality factors of several 100,000 in the 10 MHz eigenfrequency range. Dielectric transduction ideally complements the silicon nitride strings, providing an all-electrical control scheme while retaining the large mechanical quality factor [1]. It is mediated by an inhomogeneous electric field created between adjacent electrodes. The resulting gradient field provides an integrated platform for actuation, displacement detection, frequency tuning as well as strong mode coupling. Dielectrically controlled silicon nitride strings are an ideal testbed to explore a variety of dynamical phenomena ranging from multimode coupling to coherent control. The focus of this presentation will be on the nonlinear dynamics of a driven high Q string. For relatively weak driving, emergent satellite peak reminiscent of thermomechanical squeezing are understood in the framework of the cubic nonlinearity of the Duffing model [2]. For stronger driving, an abnormal response heralds dynamics beyond the Duffing model [3]. [1] Q. P. Unterreithmeier et al., Universal transduction scheme for nanomechanical systems based on dielectric forces, Nature 458, 1001 (2009). [2] J. S. Huber, G. Rastelli, M. J. Seitner, J. Kölbl, W. Belzig, M. I. Dykman, and E. M. Weig, “Spectral Evidence of Squeezing of a Weakly Damped Driven Nanomechanical Mode”, Phys. Rev. X 10, 021066 (2020). [3] J. S. Ochs, G. Rastelli, M. J. Seitner, M. I. Dykman, and E. M. Weig, Resonant nonlinear response of a nanomechanical system with broken symmetry, arXiv:2108.13649 (2021     «

Doubly-clamped pre-stressed silicon nitride string resonators excel as high Q nanomechanical systems enabling room temperature quality factors of several 100,000 in the 10 MHz eigenfrequency range. Dielectric transduction ideally complements the silicon nitride strings, providing an all-electrical control scheme while retaining the large mechanical quality factor [1]. It is mediated by an inhomogeneous electric field created between adjacent electrodes. The resulting gradient field pro...     »