Electron-optical phonon coupling in suspended bilayer graphene

TL;DR

This study investigates how electron-optical phonon interactions dominate heat transfer in suspended bilayer graphene at higher electron energies, providing experimental data that aligns with theoretical models.

Contribution

It reveals that regular electron-optical phonon scattering, rather than supercollision processes, is the main heat transfer mechanism in bilayer graphene at energies above 0.15 eV.

Findings

Electron-optical phonon scattering dominates heat transfer at high energies.

Experimental results agree with theoretical estimates including zone edge and zone center phonons.

Heat flow via supercollision scattering is less significant in bilayer graphene.

Abstract

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 $ \gtrsim 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.