Nonlinear Damping in Graphene Resonators
  Based on a continuum mechanical model for single-layer graphene we propose and analyze a microscopic mechanism for dissipation in nanoelectromechanical 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 bias and ac voltages, one can cross over from a linear to a nonlinear-damping dominated regime. We discuss the behavior of the effective quality factor in this context. 
Alexander Croy, Daniel Midtvedt, Andreas Isacsson, and Jari M. Kinaret
cond-mat.mes-hall