Speaker
Marcello Porta
(Zurich Univ.)
Description
Graphene is a recently discovered material, which can be
considered as the first realization of a two-dimensional crystal. Its
unique physical properties elicited great interest in the condensed matter
physics community, both from a theoretical and an experimental point of
view.
Remarkably, some interesting features of graphene can be understood from a
mathematically rigorous viewpoint. In this talk, I will consider the
Hubbard model on the honeycomb lattice at half-filling, as a model for
undoped graphene in the presence of short-range interactions. I will
present a rigorous proof of the universality of the optical conductivity,
which agrees with recent experiments: the conductivity has a universal
value, which does not depend on the microscopic details of the model. In
particular, there are no interaction corrections, provided that the
interaction is weak enough. Also, I will report about recent progress in
the understanding of the universality of the Hall conductivity in a related
model, the interacting Haldane model. The results are based on a rigorous
formulation of the Wilsonian renormalization group and on Ward identities.
This is joint work with A. Giuliani and V. Mastropietro.
Primary author
Marcello Porta
(Univ. Zurich)
