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

Abstract

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 Bogoliubov-Parasiuk-Hepp-Zimmermann prescription. Non-standard Ward identities imply that divergent subgraphs (related to Fermi velocity renormalization) contribute to the renormalized optical conductivity. Proceeding either via densitydensity or via current-current correlation functions, a single well-defined value is obtained: $$ \mathcal{C}=\left.\left(19-6\pi \right)/12\right)=0.01 $$ C = 19 − 6 π / 12 = 0.01 in agreement with the result first obtained by Mishchenko and which is compatible with experimental uncertainties.