Abstract
We study a doped two-dimensional bosonic Hubbard model with two hard-core species using quantum Monte Carlo simulations. With doping we find five distinct phases, including a normal liquid at higher temperature, an antiferromagnetically ordered Mott insulator, a region of coexistent antiferromagnetic and superfluid phases near half filling, and farther away from half filling, a superfluid phase and a phase-separated ferromagnet. In the latter, the heavy species has Mott behavior with integer fillings, while the light species shows Mott and superfluid behaviors. The global entropy of this phase is relatively high which may provide a new avenue to obtain a polarized phase or a Mott insulator in cold-atom experiments.
- Received 20 December 2012
DOI:https://doi.org/10.1103/PhysRevB.88.161101
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