Non-volatile rewritable frequency tuning of a nanoelectromechanical resonator using photoinduced doping

TL;DR

This paper introduces a scalable, rewritable, and persistent frequency tuning method for graphene-based nanoelectromechanical resonators using photoinduced doping, enabling precise control in large-scale NEMS arrays.

Contribution

The authors demonstrate a novel photoinduced doping technique for persistent, rewritable frequency tuning of graphene NEMS using focused laser and electrical contacts.

Findings

Achieved persistent frequency tuning via photoinduced doping.

Enabled rewritable and scalable tuning of graphene NEMS.

Provided a method for local strain control in NEMS arrays.

Abstract

Tuning the frequency of a resonant element is of vital importance in both the macroscopic world, such as when tuning a musical instrument, as well as at the nanoscale. In particular, precisely controlling the resonance frequency of isolated nanoelectromechanical resonators (NEMS) has enabled innovations such as tunable mechanical filtering and mixing as well as commercial technologies such as robust timing oscillators. Much like their electronic device counterparts, the potential of NEMS grows when they are built up into large-scale arrays. Such arrays have enabled neutral-particle mass spectroscopy and have been proposed for ultralow-power alternatives to traditional analog electronics as well as nanomechanical information technologies like memory, logic, and computing. A fundamental challenge to these applications is to precisely tune the vibrational frequency and coupling of all resonators in the array, since traditional tuning methods, like patterned electrostatic gating or dielectric tuning, become intractable when devices are densely packed. Here, we demonstrate a persistent, rewritable, scalable, and high-speed frequency tuning method for graphene-based NEMS. Our method uses a focused laser and two shared electrical contacts to photodope individual resonators by simultaneously applying optical and electrostatic fields. After the fields are removed, the trapped charge created by this process persists and applies a local electrostatic tension to the resonators, tuning their frequencies. By providing a facile means to locally address the strain of a NEMS resonator, this approach lays the groundwork for fully programmable large-scale NEMS lattices and networks.