Stochastic nodal surfaces in quantum Monte Carlo calculations
Abstract
Treating the fermionic ground state problem as a constrained stochastic optimization problem, a formalism for fermionic quantum Monte Carlo is developed that makes no reference to a trial wavefunction. Exchange symmetry is enforced by nonlocal terms appearing in the Green's function corresponding to a new kind of walker propagation. Complemented by a treatment of diffusion that encourages the formation of a stochastic nodal surface, we find that an approximate long-range extension of walker cancellations can be employed without introducing significant bias, reducing the number of walkers required for a stable calculation. A proof-of-concept implementation is shown to give a stable fermionic ground state for simple harmonic and atomic systems.
Cite
@article{arxiv.2001.02215,
title = {Stochastic nodal surfaces in quantum Monte Carlo calculations},
author = {Michael Hutcheon},
journal= {arXiv preprint arXiv:2001.02215},
year = {2020}
}