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 inter-species interactions are smaller than the intra-species 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 two and the superfluid can be either of second or first order depending on the relative values of the interactions, whereas the transitions are continuous in all other cases.

10 pages, 17 figures

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Cited by in corpus (18)

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• Quantum tricriticality at the superfluid-insulator transition of binary Bose mixtures
• Interacting spin-1 bosons in a two-dimensional optical lattice
• Exotic phases of interacting p-band bosons
• Segregated quantum phases of dipolar bosonic mixtures in two-dimensional optical lattices
• Bose-Einstein condensation and critical behavior of two-component bosonic gases
• Phase diagram and multicritical behaviors of mixtures of 3D bosonic gases
• Finite temperature phase diagram of spin-1/2 bosons in two-dimensional optical lattice
• Quantum and Thermal Phase Transitions in a Bosonic Atom-Molecule Mixture in a Two-dimensional Optical Lattice
• Phase Diagrams of Antiferromagnetic Spin-1 Bosons on Square Optical Lattice with the Quadratic Zeeman Effect
• Competing supersolids of Bose-Bose mixtures in a triangular lattice
• Magnetic Phase Transition in the Ground-State Phase Diagram of Binary Bose Gases in Optical Lattices
• Spin-1 Bose Hubbard model with nearest neighbour extended interaction
• Bosonic Kondo-Hubbard model
• Competing exotic quantum phases of spin-$1/2$ ultra-cold lattice bosons with extended spin interactions
• Out-of-equilibrium dynamics of Bose-Bose mixtures in optical lattices
• Quantum phases of a spin-1 ultracold Bose gas with three body interactions
• Effects of an attractive three body interaction on a spin-1 Bose Hubbard model