Resumen: 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 wave functions which extend Gaussian states by means of nonlinear canonical transformations (NLCTs) 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. Idioma: Inglés DOI: 10.1103/PhysRevB.107.035121 Año: 2023 Publicado en: Physical Review B 107, 3 (2023), 035121 [9 pp.] ISSN: 2469-9950 Factor impacto JCR: 3.2 (2023) Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 201 / 439 = 0.458 (2023) - Q2 - T2 Categ. JCR: PHYSICS, CONDENSED MATTER rank: 31 / 79 = 0.392 (2023) - Q2 - T2 Categ. JCR: PHYSICS, APPLIED rank: 62 / 179 = 0.346 (2023) - Q2 - T2 Factor impacto CITESCORE: 6.3 - Condensed Matter Physics (Q1) - Electronic, Optical and Magnetic Materials (Q2)