Strong-coupling expansion for the two-species Bose-Hubbard model

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.033630· OSTI ID:21450624

Iskin, M ^[1]

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1. Department of Physics, Koc University, Rumelifeneri Yolu, 34450 Sariyer, Istanbul (Turkey)

To analyze the ground-state phase diagram of Bose-Bose mixtures loaded into d-dimensional hypercubic optical lattices, we perform a strong-coupling power-series expansion in the kinetic energy term (plus a scaling analysis) for the two-species Bose-Hubbard model with onsite boson-boson interactions. We consider both repulsive and attractive interspecies interaction, and obtain an analytical expression for the phase boundary between the incompressible Mott insulator and the compressible superfluid phase up to third order in the hoppings. In particular, we find a re-entrant quantum phase transition from paired superfluid (superfluidity of composite bosons, i.e., Bose-Bose pairs) to Mott insulator and again to a paired superfluid in all one, two, and three dimensions, when the interspecies interaction is sufficiently large and attractive. We hope that some of our results could be tested with ultracold atomic systems.

• OSTI ID: 21450624
• Journal Information: Physical Review. A, Vol. 82, Issue 3; Other Information: DOI: 10.1103/PhysRevA.82.033630; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
BOSONS
COUPLING
HUBBARD MODEL
KINETIC ENERGY
MIXTURES
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
POWER SERIES
SUPERFLUIDITY
CRYSTAL MODELS
DIAGRAMS
DISPERSIONS
ENERGY
INFORMATION
MATHEMATICAL MODELS
SERIES EXPANSION