Coupling graphene nanomechanical motion to a single-electron transistor

TL;DR

This paper demonstrates the coupling of a graphene nanomechanical resonator with a single-electron transistor, revealing tunable resonance, high quality factor, and potential for ultra-sensitive mass and force detection.

Contribution

It is the first to experimentally explore charge-mechanical coupling in graphene resonators using a SET as a detector, showing significant frequency shifts and enhanced nonlinearity.

Findings

Resonance frequency tuned from 82 MHz to 100 MHz

Quality factor exceeded 30000

Achieved mass resolution of ~0.55*10^(-21) g

Abstract

Graphene-based electromechanical resonators have attracted much interest recently because of the outstanding mechanical and electrical properties of graphene and their various applications. However, the coupling between mechanical motion and charge transport has not been explored in graphene. Here, we studied the mechanical properties of a suspended 50-nm-wide graphene nanoribbon, which also acts as a single-electron transistor (SET) at low temperature. Using the SET as a sensitive detector, we found that the resonance frequency could be tuned from 82 MHz to 100 MHz and the quality factor exceeded 30000. The strong charge-mechanical coupling was demonstrated by observing the SET induced ~140 kHz resonance frequency shifts and mechanical damping. We also found that the SET can enhance the nonlinearity of the resonator. Our SET-coupled graphene mechanical resonator could approach an ultra-sensitive mass resolution of ~0.55*10^(-21) g and a force sensitivity of ~1.9*10^(-19) N/(Hz)^(1/2), and can be further improved. These properties indicate that our device is a good platform both for fundamental physical studies and potential applications.