Ground-state phase diagram of spin-(1/2) bosons in a two-dimensional optical lattice

Journal Article · Mon Aug 01 04:00:00 EDT 2011 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PHYSREVB.84.064529· OSTI ID:21596846

Forges de Parny, L de; Hebert, F ^[1]; Rousseau, V G ^[2]; Scalettar, R T ^[3]; Batrouni, G G ^[1]

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1. INLN, Universite de Nice-Sophia Antipolis, CNRS, 1361 Route des Lucioles, 06560 Valbonne (France)
2. Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803 (United States)
3. Physics Department, University of California, Davis, California 95616 (United States)

We study a two-species bosonic Hubbard model on a two-dimensional square lattice by means of quantum Monte Carlo simulations. In addition to the usual contact repulsive interactions between the particles, the Hamiltonian has an interconversion term which allows the transformation of two particles from one species to the other. The phases are characterized by their solid or superfluid properties and by their polarization, i.e., the difference in the populations. When interspecies interactions are smaller than the intraspecies ones, the system is unpolarized, whereas in the opposite case the system is unpolarized in even Mott insulator lobes and polarized in odd Mott lobes and also in the superfluid phase. We show that in the latter case the transition between the Mott insulator of total density 2 and the superfluid can be of either second or first order depending on the relative values of the interactions, whereas the transitions are continuous in all other cases.

• OSTI ID: 21596846
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Issue: 6 Vol. 84; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANGULAR MOMENTUM
BOSONS
CALCULATION METHODS
COMPUTERIZED SIMULATION
CRYSTAL LATTICES
CRYSTAL MODELS
CRYSTAL STRUCTURE
DIAGRAMS
ELECTROMAGNETIC RADIATION
ENERGY LEVELS
GROUND STATES
HAMILTONIANS
HUBBARD MODEL
INFORMATION
INTERACTIONS
INTERFERENCE
LASER RADIATION
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
MONTE CARLO METHOD
PARTICLE PROPERTIES
PHASE DIAGRAMS
POLARIZATION
QUANTUM OPERATORS
RADIATIONS
SIMULATION
SOLIDS
SPIN
STARK EFFECT
SUPERFLUIDITY
TETRAGONAL LATTICES
TWO-DIMENSIONAL CALCULATIONS