Artificial staggered magnetic field for ultracold atoms in optical lattices

Journal Article · Mon Feb 15 04:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.023404· OSTI ID:21408257

Lim, Lih-King; Smith, C Morais ^[1]; Hemmerich, Andreas ^[2]

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1. Institute for Theoretical Physics, Utrecht University, Leuvenlaan 4, NL-3584 CE Utrecht (Netherlands)
2. Institut fuer Laser-Physik, Universitaet Hamburg, Luruper Chaussee 149, D-22761 Hamburg (Germany)

A time-dependent optical lattice with staggered particle current in the tight-binding regime was considered that can be described by a time-independent effective lattice model with an artificial staggered magnetic field. The low-energy description of a single-component fermion in this lattice at half-filling is provided by two copies of ideal two-dimensional massless Dirac fermions. The Dirac cones are generally anisotropic and can be tuned by the external staggered flux {phi}. For bosons, the staggered flux modifies the single-particle spectrum such that in the weak coupling limit, depending on the flux {phi}, distinct superfluid phases are realized. Their properties are discussed, the nature of the phase transitions between them is established, and Bogoliubov theory is used to determine their excitation spectra. Then the generalized superfluid-Mott-insulator transition is studied in the presence of the staggered flux and the complete phase diagram is established. Finally, the momentum distribution of the distinct superfluid phases is obtained, which provides a clear experimental signature of each phase in ballistic expansion experiments.

• OSTI ID: 21408257
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 81; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSONS
COUPLING
DIAGRAMS
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMIONS
INFORMATION
MAGNETIC FIELDS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SPECTRA
SUPERFLUIDITY
TIME DEPENDENCE