title: Intrinsic loss due to unstable modes in graphene.
abstract: The mechanism of dissipation operative at the nanoscale remains poorly understood for most cases. In this work, using molecular dynamics simulations, we show that the unstable out-of-plane mode leads to the absorption of energy from the in-plane motion in graphene. The in-plane vibration modulates the potential energy profile for the out-of-plane modes. For the fundamental out-of-plane mode in the loading direction, the minimum of the potential energy shifts because of in-plane compressive strain. The structure takes a finite amount of time to relax to the new potential energy configuration. A hysteresis in the out-of-plane dynamics is observed when the time period of in-plane excitation becomes comparable to the time required for this relaxation. Increasing the stiffness of the out-of-plane modes by giving an initial tensile strain leads to a considerable decrease in dissipation rate.
authors.affiliation: Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: K
authors.initials: K
authors.lastname: Kunal
authors.forename: N R
authors.initials: NR
authors.lastname: Aluru