arXiv:0902.2212 · Physical Review B
Magnetic phases of two-component ultracold bosons in an optical lattice
Andreas Hubener, Michiel Snoek, Walter Hofstetter
Abstract
We investigate spin-order of ultracold bosons in an optical lattice by means of dynamical mean-field theory. A rich phase diagram with anisotropic magnetic order is found, both for the ground state and at finite temperatures. Within the Mott insulator, a ferromagnetic to antiferromagnetic transition can be tuned using a spin-dependent optical lattice. In addition we find a supersolid phase, in which superfluidity coexists with antiferromagnetic spin order. We present detailed phase diagrams at finite temperature for the experimentally realized heteronuclear $^{87}\text{R}\text{b-}^{41}\text{K}$ mixture in a three-dimensional optical lattice.