Particle exchange in the Fourier path-integral Monte Carlo technique

Abstract

A formalism which incorporates the effects of particle exchange in the Fourier path integral Monte Carlo framework is developed. Expressions for thermal averages of static quantities as well as the kinetic and total energy for identical-particle systems are derived. For bosons, the procedure for evaluating thermal averages is analogous to that in the discretized path integral approach. For fermion systems, it is shown that the critical "negative sign" problem can be substantially reduced by defining a weight function that sums over all possible permutations. The algorithm developed is applied to two types of systems, noninteracting identical particles (bosons and fermions) in a harmonic potential and a model atomic cluster of interacting, spinless bosons.