Ground-state and dynamic properties of hard-core bosons in one-dimensional incommensurate optical lattices with harmonic trap

We study properties of the strongly repulsive Bose gas on one-dimensional incommensurate optical lattices with a harmonic trap, which can be deal with by using the exact numerical method through the Bose-Fermi mapping. We first exploit the phase transition of the hard-core bosons in the optical lattices from superfluid-to-Bose-glass phase as the strength of the incommensurate potential increases. Then we study the dynamical properties of the system after suddenly switching off the harmonic trap. We calculate the one-particle density matrices, momentum distributions, the natural orbitals and their occupations for both the static and dynamic systems. Our results indicate that the Bose-glass phase and superfluid phase display quite different properties and expansion dynamics.
Comment: 7 pages, 6 figures