Mott-insulator-to-superfluid transition in Bose-Bose mixtures in a two-dimensional lattice

Journal Article · Sun Aug 15 00:00:00 EDT 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.021601· OSTI ID:21456934

Guglielmino, M ^[1]; Penna, V ^[2]; Capogrosso-Sansone, B ^[3]

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1. Dipartimento di Fisica, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)
2. Dipartimento di Fisica and CNISM Unita di Ricerca, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)
3. Institute for Theoretical Atomic, Molecular and Optical Physics, Harvard-Smithsonian Center of Astrophysics, Cambridge, Massachusetts 02138 (United States)

We perform a numeric study (worm algorithm Monte Carlo simulations) of ultracold two-component bosons in two-dimensional optical lattices. We study how the Mott-insulator-to-superfluid transition is affected by the presence of a second superfluid bosonic species. We find that, at fixed interspecies interaction, the upper and lower boundaries of the Mott lobe are differently modified. The lower boundary is strongly renormalized even for relatively low filling factor of the second component and moderate (interspecies) interaction. The upper boundary, instead, is affected only for large enough filling of the second component. Whereas boundaries are renormalized we find evidence of polaron-like excitations. Our results are of interest for current experimental setups.

• OSTI ID: 21456934
• Journal Information: Physical Review. A, Vol. 82, Issue 2; Other Information: DOI: 10.1103/PhysRevA.82.021601; (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
ALGORITHMS
BOSE-EINSTEIN GAS
BOSONS
COMPUTERIZED SIMULATION
EXCITATION
MIXTURES
MONTE CARLO METHOD
PHASE TRANSFORMATIONS
POLARONS
SUPERFLUIDITY
TWO-DIMENSIONAL CALCULATIONS
CALCULATION METHODS
DISPERSIONS
ENERGY-LEVEL TRANSITIONS
MATHEMATICAL LOGIC
QUASI PARTICLES
SIMULATION