Optical conductivity of graphene in the presence of random lattice deformations

TL;DR

This paper investigates how random lattice deformations affect the optical conductivity of graphene, modeling deformations as a non-abelian gauge field, and finds that these effects cancel out in perturbation theory.

Contribution

It introduces a gauge field approach to model lattice deformations and demonstrates that their impact on optical conductivity vanishes perturbatively.

Findings

Corrections due to lattice deformations cancel at second order

Corrections are argued to vanish at all orders in perturbation theory

Lattice deformations do not alter optical conductivity in the studied model

Abstract

We study the influence of lattice deformations on the optical conductivity of a two-dimensional electron gas. Lattice deformations are taken into account by introducing a non-abelian gauge field into the Eucledian action of two-dimensional Dirac electrons. This is in analogy to the introduction of the gravitation in the four-dimensional quantum field theory. We examine the effect of these deformations on the averaged optical conductivity. Within the perturbative theory up to second order we show that corrections of the conductivity due to the deformations cancel each other exactly. We argue that these corrections vanish to any order in perturbative expansion.