Non-Gaussian Variational Wavefunctions for Interacting Bosons on the Lattice
Abstract
A variational method for studying the ground state of strongly interacting quantum many-body bosonic systems is presented. Our approach constructs a class of extensive variational non-Gaussian wavefunctions which extend Gaussian states by means of nonlinear canonical transformations (NLCT) on the fields of the theory under consideration. We illustrate this method with the one dimensional Bose-Hubbard model for which the proposal presented here, provides a family of approximate ground states at arbitrarily large values of the interaction strength. We find that, for different values of the interaction, the non-Gaussian NLCT-trial states sensibly improve the ground state energy estimation when the system is in the Mott phase.
Cite
@article{arxiv.2211.04320,
title = {Non-Gaussian Variational Wavefunctions for Interacting Bosons on the Lattice},
author = {Tian Qian and Jose J. Fernandez-Melgarejo and David Zueco and Javier Molina-Vilaplana},
journal= {arXiv preprint arXiv:2211.04320},
year = {2023}
}
Comments
10 pages, 2 figures