Nonlinear screening of charge impurities in graphene

TL;DR

This paper demonstrates that nonlinear effects significantly suppress charge impurity screening in graphene, challenging the applicability of linear response theory and impacting resistivity estimates.

Contribution

It introduces a nonlinear screening model for charge impurities in graphene, showing the inadequacy of linear response theory in this context.

Findings

Nonlinear screening leads to strong suppression of impurity charges.

Linear response theory overestimates impurity contributions to resistivity.

Vacuum polarization effects are significant in undoped graphene.

Abstract

It is shown that a ``vacuum polarization'' induced by Coulomb potential in graphene leads to a strong suppression of electric charges even for undoped case (no charge carriers). A standard linear response theory is therefore not applicable to describe the screening of charge impurities in graphene. In particular, it overestimates essentially the contributions of charge impurities into the resistivity of graphene.