July 31, 2018 to August 6, 2018
Maynooth University
Europe/Dublin timezone

Competing Order in the Hexagonal Hubbard Model

Aug 3, 2018, 5:20 PM
Hall D (Arts Bldg.)

Hall D

Arts Bldg.

Talk Focus Subsection: Emergent Gauge Fields and Chiral Fermions Focus Subsection - Parallel


Prof. Lorenz von Smekal (Justus-Liebig University Giessen)


I will report on our studies of strongly correlated fermions on the hexagonal lattice with Hybrid Monte-Carlo simulations. In particular, we have determined the phase diagram in on-site U and nearest-neighbor repulsion V of the extended Hubbard model in the region V < U/3 where it can be simulated without a fermion sign problem. Several important algorithmic improvements, such as the analogue of a chiral fermion action with an exact sublattice symmetry or a complexified Hubbard field to avoid domain walls, were necessary for this unbiased study of the competition between spin-density wave and charge-density wave formation in the ground state. For V > U/3 or away from half filling the model is also well suited to diagnose and test approaches to circumvent the sign problem.

Primary author

Prof. Lorenz von Smekal (Justus-Liebig University Giessen)


Dr Dominik Smith (Justus-Liebig University Giessen) Dr Maksim Ulybyshev (Uni Wuerzburg) Dr Pavel Buividovich (Regensburg University)

Presentation materials