title: Loop updates for quantum Monte Carlo simulations in the canonical ensemble.
abstract: We present a new nonlocal updating scheme for quantum Monte Carlo simulations, which conserves particle number and other symmetries. It allows exact symmetry projection and direct evaluation of the equal-time Green's function and other observables in the canonical ensemble. The method is applicable to a wide variety of systems. We show results for bosonic atoms in optical lattices, neutron pairs in atomic nuclei, and electron pairs in ultrasmall superconducting grains.
authors.affiliation: Universiteit Gent -- UGent, Vakgroep Subatomaire en Stralingsfysica Proeftuinstraat 86, B-9000 Gent, Belgium.
authors.forename: S M A
authors.initials: SM
authors.lastname: Rombouts
authors.forename: K
authors.initials: K
authors.lastname: Van Houcke
authors.forename: L
authors.initials: L
authors.lastname: Pollet