Quantum phases of atomic boson-fermion mixtures in optical lattices

Journal Article · Sun Feb 01 04:00:00 EST 2004 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.69.021601· OSTI ID:20640672

Roth, Robert; Burnett, Keith ^[1]

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1. Institut fuer Kernphysik, Technische Universitaet Darmstadt, 64289 Darmstadt (Germany)

The zero-temperature phase diagram of a binary mixture of bosonic and fermionic atoms in a one-dimensional optical lattice is studied in the framework of the Bose-Fermi-Hubbard model. By exact numerical solution of the associated eigenvalue problems, ground state observables and the response to an external phase twist are evaluated. The stiffnesses under phase variations provide measures for the boson superfluid fraction and the fermionic Drude weight. Several distinct quantum phases are identified as functions of the strength of the repulsive boson-boson and the boson-fermion interactions. In addition to the bosonic Mott-insulator phase, two other insulating phases are found, where both the bosonic superfluid fraction and the fermionic Drude weight vanish simultaneously. One of these double-insulator phases exhibits a crystalline diagonal long-range order, while the other is characterized by spatial separation of the two species.

• OSTI ID: 20640672
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 69; 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
BINARY MIXTURES
BOSONS
EIGENFUNCTIONS
EIGENVALUES
FERMIONS
FLEXIBILITY
GROUND STATES
HUBBARD MODEL
NUMERICAL SOLUTION
ONE-DIMENSIONAL CALCULATIONS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SUPERFLUIDITY
TUNNEL EFFECT