Substrate limited electron dynamics in graphene

TL;DR

This paper investigates how polarizable substrates like SiO2 and SiC affect electron dynamics in graphene, revealing substrate-induced broadening of quasiparticle spectra and a density-dependent resistivity increase near room temperature.

Contribution

It demonstrates the impact of substrate polar modes on electron transport in graphene, highlighting the substrate's role as a limiting factor in electron mobility.

Findings

Substrate polar modes cause quasiparticle broadening in graphene.

Resistivity sharply increases around room temperature due to substrate effects.

Doped bilayer graphene shows weaker substrate influence due to its band structure.

Abstract

We study the effects of polarizable substrates such as SiO2 and SiC on the carrier dynamics in graphene. We find that the quasiparticle spectrum acquires a finite broadening due to the long-range interaction with the polar modes at the interface between graphene and the substrate. This mechanism results in a density dependent electrical resistivity, that exhibits a sharp increase around room temperature, where it can become the dominant limiting factor of electron transport. The effects are weaker in doped bilayer graphene, due to the more conventional parabolic band dispersion.