Numerical study of the hard-core Bose-Hubbard model on an infinite square lattice

Abstract

We present a study of the hard-core Bose-Hubbard model at zero temperature on an infinite square lattice using the infinite projected entangled pair state algorithm [J. Jordan, R. Or\'us, G. Vidal, F. Verstraete, and J. I. Cirac, Phys. Rev. Lett. 101, 250602 (2008)]. Throughout the whole phase diagram our values for the ground-state energy, particle density, and condensate fraction accurately reproduce those previously obtained by other methods. We also explore ground-state entanglement, compute two-point correlators, and conduct a fidelity-based analysis of the phase diagram. Furthermore, for illustrative purposes we simulate the response of the system when a perturbation is suddenly added to the Hamiltonian.