Competing exotic quantum phases of spin-$1/2$ ultra-cold lattice bosons with extended spin interactions
Abstract
Advances in pure optical trapping techniques now allow the creation of degenerate Bose gases with internal degrees of freedom. Systems such as Rb, K or Na in the hyperfine state offer an ideal platform for studying the interplay of superfluidity and quantum magnetism. Motivated by the experimental developments, we study ground state phases of a two-component Bose gas loaded on an optical lattice. The system is described effectively by the Bose-Hubbard Hamiltonian with onsite and near neighbor spin-spin interactions. An important feature of our investigation is the inclusion of interconversion (spin flip) terms between the two species, which has been observed in optical lattice experiments. Using mean-field theory and quantum Monte Carlo simulations, we map out the phase diagram of the system. A rich variety of phases is identified, including antiferromagnetic (AF) Mott insulators, ferromagnetic and AF superfluids.
Keywords
Cite
@article{arxiv.1505.00722,
title = {Competing exotic quantum phases of spin-$1/2$ ultra-cold lattice bosons with extended spin interactions},
author = {Chia-Chen Chang and Valéry G. Rousseau and Richard T. Scalettar and George G. Batrouni},
journal= {arXiv preprint arXiv:1505.00722},
year = {2015}
}
Comments
11 pages, 10 figures, revised version