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

Abstract

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.

Authors:
;  [1];  [2];  [3];  [1];  [4]
  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)
  4. (Singapore)
Publication Date:
OSTI Identifier:
21596846
Resource Type:
Journal Article
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Volume: 84; Journal Issue: 6; Other Information: DOI: 10.1103/PhysRevB.84.064529; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1098-0121
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BOSONS; COMPUTERIZED SIMULATION; GROUND STATES; HAMILTONIANS; HUBBARD MODEL; INTERACTIONS; INTERFERENCE; LASER RADIATION; MONTE CARLO METHOD; PHASE DIAGRAMS; POLARIZATION; SOLIDS; SPIN; STARK EFFECT; SUPERFLUIDITY; TETRAGONAL LATTICES; TWO-DIMENSIONAL CALCULATIONS; ANGULAR MOMENTUM; CALCULATION METHODS; CRYSTAL LATTICES; CRYSTAL MODELS; CRYSTAL STRUCTURE; DIAGRAMS; ELECTROMAGNETIC RADIATION; ENERGY LEVELS; INFORMATION; MATHEMATICAL MODELS; MATHEMATICAL OPERATORS; PARTICLE PROPERTIES; QUANTUM OPERATORS; RADIATIONS; SIMULATION

Citation Formats

Forges de Parny, L. de, Hebert, F., Rousseau, V. G., Scalettar, R. T., Batrouni, G. G., and Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3 Singapore 117542. Ground-state phase diagram of spin-(1/2) bosons in a two-dimensional optical lattice. United States: N. p., 2011. Web. doi:10.1103/PHYSREVB.84.064529.
Forges de Parny, L. de, Hebert, F., Rousseau, V. G., Scalettar, R. T., Batrouni, G. G., & Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3 Singapore 117542. Ground-state phase diagram of spin-(1/2) bosons in a two-dimensional optical lattice. United States. doi:10.1103/PHYSREVB.84.064529.
Forges de Parny, L. de, Hebert, F., Rousseau, V. G., Scalettar, R. T., Batrouni, G. G., and Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3 Singapore 117542. Mon . "Ground-state phase diagram of spin-(1/2) bosons in a two-dimensional optical lattice". United States. doi:10.1103/PHYSREVB.84.064529.
@article{osti_21596846,
title = {Ground-state phase diagram of spin-(1/2) bosons in a two-dimensional optical lattice},
author = {Forges de Parny, L. de and Hebert, F. and Rousseau, V. G. and Scalettar, R. T. and Batrouni, G. G. and Centre for Quantum Technologies, National University of Singapore, 2 Science Drive 3 Singapore 117542},
abstractNote = {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.},
doi = {10.1103/PHYSREVB.84.064529},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
issn = {1098-0121},
number = 6,
volume = 84,
place = {United States},
year = {2011},
month = {8}
}