Interacting Electrons in Graphene: Fermi Velocity Renormalization and Optical Response

Abstract

We have developed a Hartree-Fock theory for electrons on a honeycomb lattice aiming to solve a long-standing problem of the Fermi velocity renormalization in graphene. Our model employs no fitting parameters (like an unknown band cutoff) but relies on a topological invariant (crystal structure function) that makes the Hartree-Fock sublattice spinor independent of the electron-electron interaction. Agreement with the experimental data is obtained assuming static self-screening including local field effects. As an application of the model, we derive an explicit expression for the optical conductivity and discuss the renormalization of the Drude weight. The optical conductivity is also obtained via precise quantum Monte Carlo calculations which compares well to our mean-field approach.

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

“…There has therefore been extensive theoretical works during the past decade devoted to understanding the intriguing effect of interactions on the optical conductivity of graphene in the collisionless limit, see, e.g., refs. [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], see also [30] for a short review. The latter can be defined via a density-density correlation function:…”

Plasmonics in Topological Insulators: Spin–Charge Separation, the Influence of the Inversion Layer, and Phonon–Plasmon Coupling

“…Moreover, the Drude weight of the interacting system is larger than the Drude weight of the noninteracting system. [59][60][61] The experimental result of 90% spectral weight of the TSS thus includes possible interaction effects. Neglecting those, as done by our theory above, would lower the result to become closer to the 70%-80%, first obtained in Ref.…”

Field theoretic renormalization study of reduced quantum electrodynamics and applications to the ultrarelativistic limit of Dirac liquids

“…Indeed, in the non-relativistic limit there is often no definitive agreement on the precise value of important quantities directly related to interaction effects; in relation with graphene, let's for example mention two quantities that have been the subject of extensive work arXiv:1801.10385v2 [hep-th] 4 Apr 2018 2 during the last decade: the value of the interaction correction to the optical conductivity, see, e.g., Refs. [41][42][43][44][45][46][47][48][49][50][51][52] and the value of the critical coupling constant for dynamical gap generation, see, e.g., Refs. .…”