Competing exotic quantum phases of spin-1/2 ultracold lattice bosons with extended spin interactions

Article

关键词: ATOMIC-HYDROGEN;    BOSE;    SUPERFLUID;    CONDENSATION;    MIXTURES;    GASES;   

DOI  :  10.1103/PhysRevB.92.054506

来源: SCIE

【 摘 要 】

Advances in pure optical trapping techniques now allow the creation of degenerate Bose gases with internal degrees of freedom. Systems such as Rb-87, K-39, or Na-23 in the F = 1 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 on-site 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 and ferromagnetic and AF superfluids.

【 授权许可】

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