A quantum system can undergo a continuous phase transition at the absolute zero of
temperature as some parameter entering its Hamiltonian is varied. These transitions are …

Josephson-junction arrays are ideal model systems to study a variety of phenomena such as
phase transitions, frustration effects, vortex dynamics and chaos. In this review, we focus on …

The dynamics of an ultracold dilute gas of bosonic atoms in an optical lattice can be
described by a Bose-Hubbard model where the system parameters are controlled by laser …

A strong-coupling expansion for the phase boundary of the (incompressible) Mott insulator is
presented for the Bose-Hubbard model. Both the pure case and the disordered case are …

We describe the nature of charge transport at nonzero temperatures (T) above the two-
dimensional (d) superfluid-insulator quantum-critical point. We argue that the transport is …

The first reliable analytic calculation of the phase diagram of the Bose gas on a d-
dimensional lattice with on-site repulsion is presented. In one dimension, the analytic …

Universal properties of the zero-temperature superconductor-insulator transition in two-
dimensional amorphous films are studied by extensive Monte Carlo simulations of bosons in …

We use two quantum Monte Carlo algorithms to map out the phase diagram of the two-
dimensional hardcore boson Hubbard model with near (V 1) and next near (V 2) neighbor …

Abstract One-dimensional (1D) arrays of small-capacitance Josephson junctions
demonstrate a sharp transition, from Josephson-like behavior to the Coulomb blockade of …

We investigate the properties of strongly interacting bosons in two dimensions at zero
temperature using mean-field theory, a variational ansatz for the ground-state wave function …