Coupling between electrons and optical phonons in suspended bilayer graphene

Using electrical transport experiments and shot noise thermometry, we investigate electron-phonon heat transfer rate in a suspended bilayer graphene. Contrary to monolayer graphene with heat flow via three-body supercollision scattering, we find that regular electron-optical-phonon scattering in bilayer graphene provides the dominant scattering process at electron energies greater than or similar to 0.15 eV. We determine the strength of these intrinsic heat flow processes of bilayer graphene and find good agreement with theoretical estimates when both zone edge and zone center optical phonons are taken into account.