Determinantal and worldline quantum Monte Carlo methods for many-body systems

Journal Article · Tue Jun 15 04:00:00 EDT 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.47.16131· OSTI ID:6520172

Vekic, M; White, S R ^[1]

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1. Department of Physics, University of California, Irvine, California 92717 (United States)

We examine three different quantum Monte Carlo methods for studying systems of interacting particles. The determinantal quantum Monte Carlo method is compared to two different worldline simulations. The first worldline method consists of a simulation carried out in the real-space basis, while the second method is implemented using as basis the eigenstates of the Hamiltonian on blocks of the two-dimensional lattice. We look, in particular, at the Hubbard model on a 4[times]4 lattice with periodic boundary conditions. The block method is superior to the real-space method in terms of the computational cost of the simulation, but shows a much worse negative sign problem. For larger values of [ital U] and away from half-filling it is found that the real-space method can provide results at lower temperatures than the determinantal method. We show that the sign problem in the block method can be slightly improved by an appropriate choice of basis.

• OSTI ID: 6520172
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 47:24; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

665000* -- Physics of Condensed Matter-- (1992-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CALCULATION METHODS
COMPUTERIZED SIMULATION
CRYSTAL MODELS
FERMIONS
HUBBARD MODEL
INTERACTIONS
MANY-BODY PROBLEM
MATHEMATICAL MODELS
MONTE CARLO METHOD
QUANTIZATION
SIMULATION