Coupled two-component atomic gas in an optical lattice

Abstract

We present an ab initio study of the ground state of an ideal coupled two-component gas of ultracold atoms in a one dimensional optical lattice, either bosons or fermions. Due to the internal two-level structure of the atoms, the Brillouin zone is twice as large as imposed by the periodicity of the lattice potential. This is reflected in the Bloch dispersion curves, where the energy bands regularly possess several local minima. As a consequence, when the system parameters are tuned across a resonance condition, a non-zero temperature phase transition occurs which arises from an interplay between internal and kinetic atomic energies. For fermions, this phase transition is of topological character since the structure of the Fermi surface is changed across the critical value. It is shown that these phenomena are also expected to occur for two and three dimensional optical lattices.

10 pages, 7 figures

References in corpus (7)

• Supersolid hardcore bosons on the triangular lattice
• Implementation of Spin Hamiltonians in Optical Lattices
• Mixtures of Bosonic and Fermionic Atoms in Optical Lattices
• Fermi Surface Reconstruction without Breakdown of Kondo Screening at Quantum Critical Point
• Spin-1 bosons with coupled ground states in optical lattices
• First- and second-order superfluid--Mott-insulator phase transitions of spin-1 bosons with coupled ground states in optical lattices
• Pair condensation of bosonic atoms induced by optical lattices

Cited by in corpus (2)

• Coupling internal atomic states in a two-component Bose-Einstein condensate via an optical lattice: Extended Mott-superfluid transitions
• Zero-temperature phase transitions in dilute bosonic superfluids on a lattice