Supersolidity from defect-condensation in the extended boson Hubbard model
Abstract
We study the ground state phase diagram of the hard-core extended boson Hubbard model on the square lattice with both nearest- (nn) and next-nearest-neighbor (nnn) hopping and repulsion, using Gutzwiller mean field theory and quantum Monte Carlo simulations. We observe the formation of supersolid states with checkerboard, striped, and quarter-filled crystal structures, when the system is doped away from commensurate fillings. In the striped supersolid phase, a strong anisotropy in the superfluid density is obtained from the simulations; however, the transverse component remains finite, indicating a true two-dimensional superflow. We find that upon doping, the striped supersolid transitions directly into the supersolid with quarter-filled crystal structure, via a first-order stripe melting transition.
Cite
@article{arxiv.0708.1807,
title = {Supersolidity from defect-condensation in the extended boson Hubbard model},
author = {Yu-Chun Chen and Roger G. Melko and Stefan Wessel and Ying-Jer Kao},
journal= {arXiv preprint arXiv:0708.1807},
year = {2008}
}
Comments
Revtex 4, 6 pages, 9 figures