Two-state Bose-Hubbard model in the hard-core boson limit

Abstract

Phase transition into the phase with Bose-Einstein (BE) condensate in the two-band Bose-Hubbard model with the particle hopping in the excited band only is investigated. Instability connected with such a transition (which appears at excitation energies $\delta <|t_0^{\prime }|$, where $|t_0^{\prime }|$ is the particle hopping parameter) is considered. The re-entrant behaviour of spinodales is revealed in the hard-core boson limit in the region of positive values of chemical potential. It is found that the order of the phase transition undergoes a change in this case and becomes the first one; the re-entrant transition into the normal phase does not take place in reality. First order phase transitions also exist at negative values of $\delta$ (under the condition $\delta >{\delta }_{\mathrm{crit}}\approx -0.12|t_0^{\prime }|$). At $\mu <0$ the phase transition mostly remains to be of the second order. The behaviour of the BE-condensate order parameter is analyzed, the $(\Theta ,\mu )$ and $(|t_0^{\prime }|,\mu )$ phase diagrams are built and localizations of tricritical points are established. The conditions are found at which the separation on the normal phase and the phase with the BE condensate takes place.

14 pages, 12 figures

References in corpus (23)

• Many-Body Physics with Ultracold Gases
• Quantum phase transition from a superfluid to a Mott insulator in a gas of ultracold atoms
• Cold bosonic atoms in optical lattices
• Collapse and Revival of the Matter Wave Field of a Bose-Einstein Condensate
• Monte Carlo study of two-dimensional Bose-Hubbard model
• Spinor Bosonic Atoms in Optical Lattices: Symmetry Breaking and Fractionalization
• State preparation and dynamics of ultracold atoms in higher lattice orbitals
• Phase diagram of the bose Hubbard model
• Quantum Phases of the Extended Bose-Hubbard Hamiltonian: Possibility of a Supersolid State of Cold Atoms in Optical Lattices
• Multi-flavor bosonic Hubbard models in the first excited Bloch band of an optical lattice
• Finite-Temperature Phase Diagram of Hard-Core Bosons in Two Dimensions
• Atomic matter of non-zero momentum Bose-Einstein condensation and orbital current order
• Correlated bosons on a lattice: Dynamical mean-field theory for Bose-Einstein condensed and normal phases
• Dynamical mean field solution of the Bose-Hubbard model
• First-order superfluid-Mott insulator transition of spinor bosons in an optical lattice
• Quantum phase transition in a multi-component Bose-Einstein condensate in optical lattices
• Phases and Transitions in the Spin-1 Bose-Hubbard Model: Systematics of a Mean-field Theory
• Spin-1 bosons with coupled ground states in optical lattices
• Multiband bosons in optical lattices
• Strong-coupling perturbation theory for the extended Bose-Hubbard model
• Itinerant-localized dual character of a strongly-correlated superfluid Bose gas in an optical lattice
• Laser probing of single-particle energy gap of a Bose gas in an optical lattice in the Mott insulator phase
• Green's Function Approach to the Bose-Hubbard Model

Cited by in corpus (5)

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• The two-state Bose-Hubbard model in the hard-core boson limit: Non-ergodicity and the Bose-Einstein condensation
• Phonon-like excitations in the two-state Bose-Hubbard model
• Bose-Einstein condensation and/or modulation of "displacements" in the two-state Bose-Hubbard model