Regensburg 2016 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 63: Low-Dimensional Systems: 2D - Theory

TT 63.11: Talk

Thursday, March 10, 2016, 12:15–12:30, H21

Efficiency of the Hybrid Quantum Monte Carlo Method for Hubbard type models. — •Stefan Beyl, Fakher F. Assaad, and Florian Goth — Institut für Theoretische Physik und Astrophysik, Universität Würzburg, Deutschland

The Hybrid Quantum Monte Carlo method has the potential advantage of reaching very large system sizes for Hubbard type models since it can scale linearly with the euclidean volume. Here we argue that the performance of the method is strongly dimension dependent. In the one-dimensional case, the fact that the fermion matrix has no zeros leads to a stable algorithm which scales more efficiently than generic auxiliary field method. In two dimensions the fermionic matrix has zeros thereby leading to a breakdown of ergodicity. We propose to use a complex Hubbard Stratonovich transformation to avoid this problem.