Adsorbate Migration Effects on Continuous and Discontinuous Temperature-Dependent Transitions in the Quality Factors of Graphene Nanoresonators

TL;DR

This study uses molecular dynamics simulations to show how adsorbate migration causes temperature-dependent transitions and discontinuities in the quality factors of graphene nanomechanical resonators, highlighting the significant impact of adsorbates on their mechanical performance.

Contribution

It reveals the mechanisms by which adsorbate migration affects the quality factors of GNMRs, including both out-of-plane and in-plane migration effects, which were previously unresolved.

Findings

Out-of-plane adsorbate migration influences temperature scaling of quality factors.

Discontinuous transition in quality factor occurs at a lower critical temperature due to in-plane migration.

Adsorbate migration significantly impacts the mechanical oscillation and quality factors of GNMRs.

Abstract

We perform classical molecular dynamics simulation to investigate the mechanisms underpinning the unresolved, experimentally-observed temperature-dependent scaling transition in the quality factors of graphene nanomechanical resonators (GNMR). Our simulations reveal that the mechanism underlying this temperature scaling phenomenon is the out-of-plane migration of adsorbates on GNMRs. Specifically, the migrating adsorbate undergoes frequent collisions with the GNMR, which strongly influences the resulting mechanical oscillation, and thus the quality factors. We also predict a discontinuous transition in the quality factor at a lower critical temperature, which results from the in-plane migration of the adsorbate. Overall, our work clearly demonstrates the strong effect of adsorbate migration on the quality factors of GNMRs.