Theory of remote phonon scattering in top-gated single-layer graphene

We extend the theory of interfacial plasmon-phonon scattering to top-gated single-layer graphene. As with bottom-gated graphene, interfacial plasmon-phonon (IPP) modes are formed from the coupling between the graphene plasmon and the surface polar phonon modes in the top and bottom oxides. We study the effect of the top oxide thickness on dynamic screening and electron-IPP coupling. The remote phonon-limited electron mobility μRP and electron scattering rates in a HfO₂-covered, SiO₂-supported single-layer graphene are computed at various electron densities n for different dielectric thickness tₒₓ. We find that μRP is much more dependent on tₒₓ at low n. They also agree with the experimentally estimated room temperature μRP from Zou et al. [Phys. Rev. Lett. 105, 126601 (2010)]. The electron density dependent μRP is predicted to be between 5500 and 240.16em0ex200 cm²V^-1s^-1 from n=10¹² to 10¹³ cm^-2 at 300 K.