Subgigahertz Multilayer-Graphene Nanoelectromechanical System Integrated with a Nanometer-Scale Silicon Transistor Driven by Reflectometry

We demonstrate the detection of mechanical oscillations of a nanoelectromechanical system (NEMS) composed of a multilayer-graphene (MLG) membrane by using a Si field-effect transistor (FET). The MLG membrane of 500 nm in length is suspended above multiple nanowire channels of the FET functioning as a sensor with high sensitivity. A microwave probe in contact with the FET is connected to double-resonant circuits composed of two inductors and capacitors, and a radio-frequency (rf) signal drives the FET in the resonant condition. When the MLG membrane functioning as a gate of the FET oscillates in mechanical resonance and modulates impedance of the FET, this modulation is monitored using a reflected signal from the resonant circuits. By adjusting the resonant condition using a variable capacitor, the mechanical oscillations of the MLG membrane are detected at 340 MHz. Such rf-signal-driven readout of the NEMS operating at subgigahertz frequency will lead to highly sensitive and functional sensors for small mass and quantum mechanics as well as timing devices.

Automated summary

We detect the mechanical oscillations of a nanoelectromechanical system (NEMS) composed of a multilayer-graphene (MLG) membrane using a Si field-effect transistor (FET) and a microwave probe connected to double-resonant circuits. The mechanical oscillations of the MLG membrane as it functions as the gate of the FET are monitored through modulation of the FET's impedance. This rf-signal-driven readout at 340 MHz allows for highly sensitive and functional sensors for small mass and quantum mechanics as well as timing devices.