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arXiv · 2211.04320

Non-Gaussian Variational Wavefunctions for Interacting Bosons on the Lattice

Tian Qian·Jose J. Fernandez-Melgarejo·David Zueco·Javier Molina-Vilaplana
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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.

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Tian Qian, Jose J. Fernandez-Melgarejo, David Zueco, Javier Molina-Vilaplana. 2022-11-08. Non-Gaussian Variational Wavefunctions for Interacting Bosons on the Lattice. https://doi.org/10.1103/physrevb.107.035121

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