Ground state properties of the disordered spin-one Bose-Hubbard model: a stochastic mean-field theory study

We study the ground state of the disordered Bose-Hubbard model for spin-1 particles by means of the stochastic mean-field theory. This approach enables the determination of the probability distributions of various physical quantities, such as the superfluid order parameter, the average site occupation number, the standard deviation of the occupation per site and the square of the spin operator per site. We show how a stochastic method, previously used in the study of localization, can be flexibly used to solve the relevant equations with great accuracy. We have determined the phase diagram, which exhibits three phases: the polar superfluid, the Mott insulating and the Bose glass. A complete characterization of the physical properties of these phases has been established.