Field theoretic renormalization study of interaction corrections to the universal ac conductivity of graphene

TL;DR

This paper uses a field theoretic renormalization approach to accurately compute the interaction corrections to the universal ac conductivity of graphene, confirming previous theoretical results and aligning with experimental data.

Contribution

It provides a two-loop renormalization calculation of the interaction correction coefficient for graphene's ac conductivity using the BPHZ scheme, addressing divergence issues.

Findings

The correction coefficient is $rac{19-6\pi}{12} \\approx 0.01$.

The result agrees with Mishchenko's earlier work.

The calculation is consistent with experimental uncertainties.

Abstract

The two-loop interaction correction coefficient to the universal ac conductivity of disorder-free intrinsic graphene is computed with the help of a field theoretic renormalization study using the BPHZ prescription. Non-standard Ward identities imply that divergent subgraphs (related to Fermi velocity renormalization) contribute to the renormalized optical conductivity. Proceeding either via density-density or via current-current correlation functions, a single well-defined value is obtained: $\mathcal{C}= (19-6\pi)/12) = 0.01$ in agreement with the result first obtained by Mishchenko and which is compatible with experimental uncertainties.