Electron scattering on microscopic corrugations in graphene

TL;DR

This paper investigates how microscopic corrugations in graphene, known as ripples, significantly influence electron scattering and mobility, highlighting their role over short-range impurities in determining electronic quality.

Contribution

It demonstrates that ripples create long-range scattering potentials affecting electron mobility, providing a new understanding of scattering mechanisms in graphene.

Findings

Ripples induce long-range scattering similar to Coulomb impurities.

Electron mobility is largely unaffected by carrier concentration.

Short-range potential scattering is less relevant for graphene's electronic quality.

Abstract

We discuss various scattering mechanisms for Dirac fermions in single-layer graphene. It is shown that scattering on a short-range potential (due to, for example, neutral impurities) is mostly irrelevant for electronic quality of graphene, which is likely to be controlled by charged impurities and ripples (microscopic corrugations of a graphene sheet). The latter are an inherent feature of graphene due to its two-dimensional nature and can also be an important factor in defining the electron mean free path. We show that certain types of ripples create a long-range scattering potential, similar to Coulomb scatterers, and result in charge-carrier mobility practically independent on carrier concentration, in agreement with experimental observations.