2006/09/30 by Olivier Juillet, O. Juillet
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum many-body systems #Theoretical and Computational Physics #cond-mat.other
paper · pdf · doi:10.1088/1367-2630/9/6/163
published as New Journal of Physics 9 (2007) 163 · Accepted for publication in New Journal of Physics
arxiv created 2007/05/30 · openalex publication_date 2007/06/14 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
We propose a new projector quantum Monte-Carlo method to investigate the ground state of ultracold fermionic atoms modelled by a lattice Hamiltonian with on-site interaction. The many-body state is reconstructed from Slater determinants that randomly evolve in imaginary-time according to a stochastic mean-field motion. The dynamics prohibits the crossing of the exact nodal surface and no sign problem occurs in the Monte-Carlo estimate of observables. The method is applied to calculate ground-state energies and correlation functions of the repulsive two-dimensional Hubbard model. Numerical results for the unitary Fermi gas validate simulations with nodal constraints.