FREQUENCY STABILITY OF STRESS-ENGINEERED NANOMECHANICAL RESONATOR AND ITS CRAMER-RAO LOWER BOUND

MINGKANG WANG; RUI ZHANG; D PEREZ MORELO; ROBERT ILIC; YUXIANG LIU; VLADIMIR AKSYUK

Vancouver, BC

Congreso; 33rd International conference on micro electro mechanical systems MEMS 2020; 2020

IEEE

We experimentally demonstrate that the relative frequency stability of a stress-engineered ≈ 28 MHz nanomechanical resonator reaches lower than 1e-6 level without external excitation. For both driven and undriven cases for up to ≈ 0.1 s averaging, the frequency uncertainty remains at the thermodynamic limit given by the Cramer-Rao lower bound (CRLB), which we derive for a classical linear harmonic oscillator subject to dissipation, thermodynamic noise, detection uncertainty and with or without external excitation. A general frequency estimator reaching the CRLB on the cavity-optomechanically detected experimental data is included. The stress-engineered nanomechanical resonator with high frequency-Quality factor ( fQ ≈ 1e12 ) and considerable frequency stability could be used for developing frequency-readout displacement sensors with no excitation required