Superfluid-insulator transition in the disordered two-dimensional Bose-Hubbard model

We investigate the superfluid-insulator transition in the disordered two-dimensional Bose-Hubbard model through quantum Monte Carlo simulations. The Bose-Hubbard model is studied in the presence of site disorder, and the quantum critical point between the Bose glass and superfluid is determined in the grand canonical ensemble at μ/U=0 (close to ρ=0.5), μ/U=0.375 (close to ρ=1), and μ/U=1 as well as in the canonical ensemble at ρ=0.5 and 1. …