Nonlinear Damping Mechanism in Mechanical Graphene Resonators.

Based on a continuum mechanical model for single-layer graphene\footnote{J. Atalaya, A. Isacsson, and J. M. Kinaret, Nano Letters 8, 4196 (2008).} we propose and analyze a microscopic mechanism for dissipation in nano-electromechanical graphene resonators. We find that coupling between flexural modes and in-plane phonons leads to linear and nonlinear damping of out-of-plane vibrations. By tuning external parameters, such as static gate voltage, one can cross over from a linear to a nonlinear-damping dominated regime. We discuss how the effective quality factor depends on parameters such as temperature, and compare our results with recent experiments.