Cold atoms in double-well optical lattices
arXiv:0812.3767 · doi:10.1103/PhysRevA.78.063610
Abstract
Cold atoms, loaded into an optical lattice with double-well sites, are considered. Pseudospin representation for an effective Hamiltonian is derived. The system in equilibrium displays two phases, ordered and disordered. The second-order phase transition between the phases can be driven either by temperature or by changing the system parameters. Collective pseudospin excitations have a gap disappearing at the phase-transition point. Dynamics of atoms is studied, when they are loaded into the lattice in an initially nonequilibrium state. It is shown that the temporal evolution of atoms, contrary to their equilibrium thermodynamics, cannot be described in the mean-field approximation, since it results in a structurally unstable dynamical system, but a more accurate description is necessary taking account of attenuation effects.
Latex file, 24 pages, 3 figures
References in corpus (14)
- Many-Body Physics with Ultracold Gases
- Theory of ultracold Fermi gases
- A High Phase-Space-Density Gas of Polar Molecules
- Bose-Einstein condensation of chromium
- Controlled exchange interaction between pairs of neutral atoms in an optical lattice
- d-wave collapse and explosion of a dipolar Bose-Einstein condensate
- Finite Temperature Models of Bose-Einstein Condensation
- All-Optical Production of Chromium Bose-Einstein Condensates
- Preparing and probing atomic number states with an atom interferometer
- Sublattice addressing and spin-dependent motion of atoms in a double-well lattice
- Structure formation during the collapse of a dipolar atomic Bose-Einstein condensate
- Quantum phases of bosons in double-well optical lattices
- Incommensurate superfluidity of bosons in a double-well optical lattice
- Bose-Einstein Condensation Temperature of Dipolar Gas in Anisotropic Harmonic Trap