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TT: Fachverband Tiefe Temperaturen
TT 63: Low-Dimensional Systems: 2D - Theory
TT 63.9: Talk
Thursday, March 10, 2016, 11:45–12:00, H21
A functional Renormalization Group calculation with high wavevector resolution for extended Hubbard models on the honeycomb lattice — •David Sánchez de la Peña1, Julian Lichtenstein1, Stefan Maier1,2, and Carsten Honerkamp1 — 1Institute for Theoretical Solid State Physics, RWTH-Aachen University, D-52056 Aachen, Germany and JARA Fundamentals of Future Information Technologies — 2Institute for Theoretical Physics, Cologne University, D-50937 Cologne, Germany
Extended Hubbard models on the honeycomb lattice exhibit a rich variety of ordering tendencies at low energies, which manifest themselves as instabilities of the normal state respect to the inclusion of electron-electron interactions. In an attempt to describe the low-energy properties of real materials with such a honeycomb structure, like graphene, we analyze the arising ordering tendencies and corresponding critical scales as a function of doping and interaction parameters. For that matter, we employ a truncated unity functional Renormalization Group treatment (TUfRG), which allows for an unbiased investigation of the competing instabilities arising in the effective low-energy theory starting from a given set of bare Coulomb interactions. Being based on channel decomposed flow equations, the wavevector resolution that can be achieved is much higher than that of N-patch fRG schemes, which also allows the inclusion of a weakly screened long-range Coulomb tail in the bare interactions.
This work was supported by the DFG-SPP 1459 ’Graphene’.