A second-quantized few-fermion Monte Carlo scheme

We propose a new Monte Carlo algorithm for the solution of the few-fermion Schrödinger equation. Antisymmetry is maintained by working in the space of N-fermion determinants for an N-fermion system. This does not solve the problem of cancelling positive and negative contributions to the wave function. The problem appears in a different form, however, due to negative signs introduced by dynamic correlations instead of statistics and appears also for boson systems in this approach. Since the determinants are constructed from plane-wave states use may be made of the long range of nuclear forces in momentum space to cancel negative and positive contributions more efficiently. Incorporation of non-radial interactions, i.e. interactions with spin dependence and tensor forces, reduces the problem to a quantitative problem.