Energy transport via multiphonon processes in graphene

Abstract

The Dirac dispersion of graphene limits the phase space available for energy transport between electrons and acoustic phonons at temperatures above the Bloch-Grueneisen temperature. Consequently, energy transport can be dominated by supercollision events, involving also other scattering processes. Scattering from flexural phonons can compensate for the large momentum transfer involved in scattering from thermal acoustic phonons, and enables similar supercollision events as disorder. Such multiphonon processes are also allowed by selection rules. I show that acoustic-flexural process can in the energy transport be of the same order of magnitude as direct flexural and acoustic phonon processes, depending on electronic screening and mechanical strain.