Quantum phase transitions in optical lattices beyond Bogoliubov approximation
Quantum Gases
2012-06-05 v3
Abstract
We study the quantum phase transition in optical lattices using ordinary Bose Hubbard Hamiltonian within two loop approximation in variational perturbation theory. We have shown that this approximation can reproduce superfluid Mott insulator transition in contrast to the simple Bogoliubov or Hartee - Fock - Popov approximations. The superfluid fraction and ground state energy per particle vs input parameters of the model are studied.
Cite
@article{arxiv.1108.4695,
title = {Quantum phase transitions in optical lattices beyond Bogoliubov approximation},
author = {H. Kleinert and Z. Narzikulov and Abdulla Rakhimov},
journal= {arXiv preprint arXiv:1108.4695},
year = {2012}
}
Comments
Extended by including comarision with Gutzwiller approach. (To be published in PRA)