Parametric amplification in MoS₂ drum resonator

Abstract

Parametric amplification is widely used in diverse areas from optics to electronic circuits to enhance low level signals by varying relevant system parameters. Parametric amplification has also been performed in several micro-nano resonators including nano-electromechanical system (NEMS) resonators based on a two-dimensional (2D) material. Here, we report the enhancement of mechanical response in a MoS drum resonator using degenerate parametric amplification. We use parametric pumping to modulate the spring constant of the MoS resonator and achieve a 10 dB amplitude gain. We also demonstrate quality factor enhancement in the resonator with parametric amplification. We investigate the effect of cubic nonlinearity on parametric amplification and show that it limits the gain of the mechanical resonator. Amplifying ultra-small displacements at room temperature and understanding the limitations of the amplification in these devices is key for using these devices for practical applications.

Phase Control of Self-Excited Parametric Resonators

“…This relationship holds for the hardening case (α > 0) as well, where the stable-branch phase slope is negative unless the (negative) nonlinear damping is decreased below the critical value. MEM and NEM resonators provide an excellent platform for confirming these dynamics because beams and membranes exhibit intrinsic nonlinear damping and electric fields can be applied to tune α. Parametric resonance has been demonstrated in many devices with η < η 0 ( [12,13,19,58,[60][61][62]) as well as η > η 0 ( [63,64]). We tune the intrinsic nonlinear damping and Duffing nonlinearity in MEM resonators to observe both regimes and demonstrate closed-loop stabilization of the unstable branch.…”

Ultra-sensitive charge detection and latch memory using MoS2-nanoresonator-based bifurcation amplifiers

“…The bending of the resonance toward lower frequencies (nonlinear frequency-softening) and the hysteresis on the low-frequency side are characteristic of a resonator with negative Duffing nonlinearity. 12,15 The hysteresis between the forward and reverse traces at V p ¼ 78 mV is minimal, indicating that the resonator is close to the critical point for the onset of Duffing nonlinearity. As V p is increased to 100 mV, a large hysteresis between the forward and reverse sweeps is observed.…”

“…8 The operation of the devices in the nonlinear regime is crucial to the implementation of the bifurcation amplifiers. Nano-electromechanical systems (NEMS) based on layered materials, with tunable mechanical nonlinearities 9 at low amplitudes of vibration [10][11][12][13][14][15][16] and extraordinary sensitivity to external stimuli, [17][18][19][20] are well suited for the implementation of bifurcation amplifiers. 8 In this work, we implement a parametrically excited bifurcation amplifier using an MoS 2 nano-resonator and demonstrate charge detection and memory with exquisite sensitivity.…”

“…We use an electrical gate for capacitive actuation of the device, and the displacement is monitored by observing the change in capacitance. 10,15 The membrane acts as the moving plate of a parallel-plate capacitor, with the gate as the stationary plate. The electrostatic force, due to the applied DC voltage (V DC g ) at the gate, pulls the membrane down, producing a strain that tunes the resonant frequency of the device.…”

“…21,22 Parametric excitation offers further advantages of minimal electrical background in the measured displacement and higher amplitudes of vibration. 15,[22][23][24] The results of forward (low to high) and reverse (high to low) frequency sweeps with parametric excitation ( Fig. 1(c).…”