Supercollision cooling in undoped graphene

Abstract

Carrier mobility in solids is generally limited by electron-impurity or electron-phonon scattering depending on the most frequently occurring event. Three body collisions between carriers and both phonons and impurities are rare; they are denoted supercollisions (SCs). Elusive in electronic transport they should emerge in relaxation processes as they allow for large energy transfers. As pointed out in Ref. \onlinecite{Song2012PRL}, this is the case in undoped graphene where the small Fermi surface drastically restricts the allowed phonon energy in ordinary collisions. Using electrical heating and sensitive noise thermometry we report on SC-cooling in diffusive monolayer graphene. At low carrier density and high phonon temperature the Joule power $P$ obeys a $P\propto T_e^3$ law as a function of electronic temperature $T_e$. It overrules the linear law expected for ordinary collisions which has recently been observed in resistivity measurements. The cubic law is characteristic of SCs and departs from the $T_e^4$ dependence recently reported for metallic graphene below the Bloch-Grüneisen temperature. These supercollisions are important for applications of graphene in bolometry and photo-detection.

References in corpus (11)

• The electronic properties of graphene
• Boron nitride substrates for high-quality graphene electronics
• Temperature dependent transport in suspended graphene
• Controlling electron-phonon interactions in graphene at ultra high carrier densities
• Electron-phonon heat transfer in monolayer and bilayer graphene
• Wedging Transfer of Nanostructures
• Hot electron cooling by acoustic phonons in graphene
• Cooling of photoexcited carriers in graphene by internal and substrate phonons
• Non-linear resistivity and heat dissipation in monolayer graphene
• Electron-phonon coupling in single walled carbon nanotubes determined by shot noise
• Thermal shot noise in top-gated single carbon nanotube field effect transistors