Regensburg 2016 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 63: Low-Dimensional Systems: 2D - Theory
TT 63.8: Vortrag
Donnerstag, 10. März 2016, 11:30–11:45, H21
High-performance functional renormalization group calculations for interacting fermions on the square lattice — •Julian Lichtenstein1,2, David Sánchez de la Peña1,2, Stefan A. Maier1,2,3, and Carsten Honerkamp1,2 — 1Institute for Theoretical Solid State Physics, RWTH Aachen University, Germany — 2JARA-FIT, Jülich-Aachen Research Alliance – Fundamentals of Future Information Technology — 3Institute for Theoretical Physics, University of Cologne, Germany
The truncated unity functional renormalization group (TUfRG) approach is a novel functional renormalization group (fRG) variant. It is based on an exchange parametrization of the two-fermion interaction [1], while the structure of the equations is inspired by the singular-mode functional renormalization group put forward by Wang et al. [2]. On the basis of speedup data gained from our implementation we show that the TUfRG facilitates efficient calculations on a large number of multi-core CPUs. In this context, it will be illustrated that a separation of the underlying equations, as it is done in the TUfRG, is numerically advantageous. In order to discuss strong and weak points of this method, we compare data for the t,t′ Hubbard model on the square lattice to those from other fRG methods. Furthermore, we analyze the effect of including longer ranged interactions in addition to the purely local Hubbard interaction.
This work was supported by DFG via RTG1995 ‘Quantum many-body methods in condensed matter systems’.
[1] C. Husemann and M. Salmhofer, PRB 79, 195125 (2009)
[2] W. S. Wang et al., PRB 85, 035414 (2012)