Exact Study of the 1D Boson Hubbard Model with a Superlattice Potential
Abstract
We use Quantum Monte Carlo simulations and exact diagonalization to explore the phase diagram of the Bose-Hubbard model with an additional superlattice potential. We first analyze the properties of superfluid and insulating phases present in the hard-core limit where an exact analytic treatment is possible via the Jordan-Wigner transformation. The extension to finite on-site interaction is achieved by means of quantum Monte Carlo simulations. We determine insulator/superfluid phase diagrams as functions of the on-site repulsive interaction, superlattice potential strength, and filling, finding that insulators with fractional occupation numbers, which are present in the hard-core case, extend deep into the soft-core region. Furthermore, at integer fillings, we find that the competition between the on-site repulsion and the superlattice potential can produce a phase transition between a Mott insulator and a charge density wave insulator, with an intermediate superfluid phase. Our results are relevant to the behavior of ultracold atoms in optical superlattices which are beginning to be studied experimentally.
Cite
@article{arxiv.cond-mat/0601681,
title = {Exact Study of the 1D Boson Hubbard Model with a Superlattice Potential},
author = {V. G. Rousseau and D. P. Arovas and M. Rigol and F. Hébert and G. G. Batrouni and R. T. Scalettar},
journal= {arXiv preprint arXiv:cond-mat/0601681},
year = {2017}
}
Comments
13 pages, 23 figures