MULTILEVEL BLOCKING APPROACH TO THE FERMION SIGN PROBLEM IN PATH-INTEGRAL MONTE-CARLO SIMULATIONS

A general algorithm toward the solution of the fermion sign problem in finite-temperature quantum Monte Carlo simulations has been formulate d for discretized fermion path integrals with nearest-neighbor interac tions in the Trotter direction. This multilevel approach systematicall y implements a simple blocking strategy in a recursive manner to synth esize the sign cancellations among different fermionic paths throughou t the whole configuration space. The practical usefulness of the metho d is demonstrated for interacting electrons in a quantum dot. [S0031-9 007(98)07713-8].