Quantum phase transitions in optical lattices beyond Bogoliubov approximation
| Autor: | Kleinert, H., Narzikulov, Z., Rakhimov, Abdulla |
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| Rok vydání: | 2011 |
| Předmět: | |
| Zdroj: | Phys. Rev. A 85, 063602 (2012) |
| Druh dokumentu: | Working Paper |
| Popis: | 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. Comment: Extended by including comarision with Gutzwiller approach. (To be published in PRA) |
| Databáze: | arXiv |
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