2003/04/30 by Alexander P. Albus, Alexander Albus, Fabrizio Illuminati +1 · 7 citations
Chemistry · Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Quantum optics and atomic interactions #Spectroscopy and Laser Applications #cond-mat #hep-th #physics.atom-ph #quant-ph
paper · pdf · doi:10.1103/physreva.68.023606
published as Phys.Rev. A68 (2003) 023606 · 11 pages, 8 figures; added discussions; conclusions and references expanded
arxiv created 2003/05/15 · openalex publication_date 2003/08/22 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
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.