Mixtures of bosonic and fermionic atoms in optical lattices

Journal Article · Fri Aug 01 04:00:00 EDT 2003 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.68.023606· OSTI ID:20640090

Albus, Alexander ^[1]; Illuminati, Fabrizio ^[2]; Eisert, Jens ^[1]

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1. Institut fuer Physik, Universitaet Potsdam, Am Neuen Palais 10, D-14469 Potsdam, (Germany)
2. Dipartimento di Fisica, Universita di Salerno, Via S. Allende, I-84081 Baronissi (Saudi Arabia), Italy and Istituto Nazionale per la Fisica della Materia, I-84081 Baronissi (SA), (Italy)

We discuss the theory of mixtures of bosonic and fermionic atoms in periodic potentials at zero temperature. We derive a general Bose-Fermi Hubbard Hamiltonian in a one-dimensional optical lattice with a superimposed harmonic trapping potential. We study the conditions for linear stability of the mixture and derive a mean-field criterion for the onset of a bosonic superfluid transition. We investigate the ground-state properties of the mixture in the Gutzwiller formulation of mean-field theory, and present numerical studies of finite systems. The bosonic and fermionic density distributions and the onset of quantum phase transitions to demixing and to a bosonic Mott-insulator are studied as a function of the lattice potential strength. The existence is predicted of a disordered phase for mixtures loaded in very deep lattices. Such a disordered phase possessing many degenerate or quasidegenerate ground states is related to a breaking of the mirror symmetry in the lattice.

• OSTI ID: 20640090
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 68; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSONS
DENSITY
DISTRIBUTION
FERMIONS
GROUND STATES
HAMILTONIANS
MEAN-FIELD THEORY
MIXTURES
NUMERICAL ANALYSIS
ONE-DIMENSIONAL CALCULATIONS
PERIODICITY
PHASE TRANSFORMATIONS
POTENTIALS
STABILITY
SUPERFLUIDITY
SYMMETRY
TRAPPING