Zero-temperature phase diagram of Bose-Fermi gaseous mixtures in optical lattices

Journal Article · Thu Apr 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.043612· OSTI ID:21408672

Polak, T P; Kopec, T K ^[1]

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1. Faculty of Physics, Adam Mickiewicz University of Poznan, Umultowska 85, PL-61-614 Poznan (Poland)

We study the ground-state phase diagram of a mixture of bosonic and fermionic cold atoms confined on two- and three-dimensional optical lattices. The coupling between bosonic fluctuations and fermionic atoms can be attractive or repulsive and has similarities with electron-phonon coupling in crystals. We investigate behavior of the mixtures in the limit, where the Bogoliubov sound velocity that dictates bosonic dynamics is comparable to the Fermi velocity, hence the retardation effects are an important part of the physics. The dynamic Lindhard response function of the fermionic density to changes in the bosonic number of particles above some critical frequency can alter the sign, and consequently the interspecies interaction between particles becomes repulsive in contrast to the static limit (instantaneous and always attractive). Considering the above, we show that the structure of the phase diagrams crucially depends on the difference in masses of the bosons and fermions. We discuss the situations where integrating out the fermionic field provides an additional interaction that can decrease or increase bosonic coherence.

• OSTI ID: 21408672
• Journal Information: Physical Review. A, Vol. 81, Issue 4; Other Information: DOI: 10.1103/PhysRevA.81.043612; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSONS
CRITICAL FREQUENCY
CRYSTALS
ELECTRON-PHONON COUPLING
FERMIONS
FLUCTUATIONS
GROUND STATES
INTERACTIONS
MASS
PHASE DIAGRAMS
RESPONSE FUNCTIONS
SOUND WAVES
THREE-DIMENSIONAL CALCULATIONS
VELOCITY
COUPLING
DIAGRAMS
ENERGY LEVELS
FUNCTIONS
INFORMATION
VARIATIONS