Comparison of Variational Approaches for the Exactly Solvable 1/r-Hubbard Chain

Дата и время публикации : 1993-07-19T12:37:58Z

Авторы публикации и институты :
Florian Gebhard
Andreas Girndt

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 23 pages + 3 figures available on request; LaTeX under REVTeX 3.0
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: We study Hartree-Fock, Gutzwiller, Baeriswyl, and combined Gutzwiller-Baeriswyl wave functions for the exactly solvable one-dimensional $1/r$-Hubbard model. We find that none of these variational wave functions is able to correctly reproduce the physics of the metal-to-insulator transition which occurs in the model for half-filled bands when the interaction strength equals the bandwidth. The many-particle problem to calculate the variational ground state energy for the Baeriswyl and combined Gutzwiller-Baeriswyl wave function is exactly solved for the~$1/r$-Hubbard model. The latter wave function becomes exact both for small and large interaction strength, but it incorrectly predicts the metal-to-insulator transition to happen at infinitely strong interactions. We conclude that neither Hartree-Fock nor Jastrow-type wave functions yield reliable predictions on zero temperature phase transitions in low-dimensional, i.e., charge-spin separated systems.

Category: Physics