Graphene nanoelectromechanical resonators for detection of modulated terahertz radiation

TL;DR

This paper introduces a graphene-based nanoelectromechanical resonator for detecting modulated terahertz radiation, leveraging plasma and mechanical resonances to significantly enhance device responsivity.

Contribution

It presents a novel graphene NEM resonator design that combines plasma and mechanical resonances for improved terahertz detection capabilities.

Findings

Resonant excitation of plasma oscillations in graphene layers.

Mechanical swinging of the graphene membrane amplifies current oscillations.

Device responsivity can be increased by up to four orders of magnitude.

Abstract

We propose and analyze the detector of modulated terahertz (THz) radiation based on the graphene field-effect transistor with mechanically floating gate made of graphene as well. The THz component of incoming radiation induces resonant excitation of plasma oscillations in graphene layers (GLs). The rectified component of the ponderomotive force between GLs invokes resonant mechanical swinging of top GL, resulting in the drain current oscillations. To estimate the device responsivity, we solve the hydrodynamic equations for the electrons and holes in graphene governing the plasma-wave response, and the equation describing the graphene membrane oscillations. The combined plasma-mechanical resonance raises the current amplitude by up to four orders of magnitude. The use of graphene as a material for the elastic gate and conductive channel allows the voltage tuning of both resonant frequencies in a wide range.