TY  - JOUR
AU  - Krieg, Stefan
AU  - Luu, Thomas
AU  - Ostmeyer, Johann
AU  - Papaphilippou, Philippos
AU  - Urbach, Carsten
TI  - Accelerating Hybrid Monte Carlo simulations of the Hubbard model on the hexagonal lattice
JO  - Computer physics communications
VL  - 236
SN  - 0010-4655
CY  - Amsterdam
PB  - North Holland Publ. Co.
M1  - FZJ-2018-06303
SP  - 15-25
PY  - 2019
AB  - We present different methods to increase the performance of Hybrid Monte Carlo simulations of the Hubbard model in two-dimensions. Our simulations concentrate on a hexagonal lattice, though can be easily generalized to other lattices. It is found that best results can be achieved using a flexible GMRES solver for matrix inversions and the second order Omelyan integrator with Hasenbusch acceleration on different time scales for molecular dynamics. We demonstrate how an arbitrary number of Hasenbusch mass terms can be included into this geometry and find that the optimal speed depends weakly on the choice of the number of Hasenbusch masses and their values. As such, the tuning of these masses is amenable to automization and we present an algorithm for this tuning that is based on the knowledge of the dependence of solver time and forces on the Hasenbusch masses. We benchmark our algorithms to systems where direct numerical diagonalization is feasible and find excellent agreement. We also simulate systems with hexagonal lattice dimensions up to 102 × 102 and Nt=64 . We find that the Hasenbusch algorithm leads to a speed up of more than an order of magnitude.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000458227100003
DO  - DOI:10.1016/j.cpc.2018.10.008
UR  - https://juser.fz-juelich.de/record/857022
ER  -