We investigate the properties of strongly interacting heteronuclear boson-boson mixtures loaded in realistic optical lattices, with particular emphasis on the physics of interfaces. In particular, we numerically reproduce the recent experimental observation that the addition of a small fraction of ${}^{41}\mathrm{K}$ induces a significant loss of coherence in ${}^{87}\mathrm{Rb}$, providing a simple explanation. We then investigate the robustness against the inhomogeneity typical of realistic experimental realizations of the glassy quantum emulsions recently predicted to occur in strongly interacting boson-boson mixtures on ideal homogeneous lattices.

• Received 21 February 2008

DOI:https://doi.org/10.1103/PhysRevLett.100.240402