Bose-Hubbard models in confining potentials: Inhomogeneous mean-field theory

Pai, RameshV and Kurdestany, JamshidMoradi and Sheshadri, K and Pandit, Rahul (2012) Bose-Hubbard models in confining potentials: Inhomogeneous mean-field theory. In: PHYSICAL REVIEW B, 85 (21).

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Abstract

We present an extensive study of Mott insulator (MI) and superfluid (SF) shells in Bose-Hubbard (BH) models for bosons in optical lattices with harmonic traps. For this we apply the inhomogeneous mean-field theory developed by Sheshadri et al. Phys. Rev. Lett. 75, 4075 (1995)]. Our results for the BH model with one type of spinless bosons agree quantitatively with quantum Monte Carlo simulations. Our approach is numerically less intensive than such simulations, so we are able to perform calculations on experimentally realistic, large three-dimensional systems, explore a wide range of parameter values, and make direct contact with a variety of experimental measurements. We also extend our inhomogeneous mean-field theory to study BH models with harmonic traps and (a) two species of bosons or (b) spin-1 bosons. With two species of bosons, we obtain rich phase diagrams with a variety of SF and MI phases and associated shells when we include a quadratic confining potential. For the spin-1 BH model, we show, in a representative case, that the system can display alternating shells of polar SF and MI phases, and we make interesting predictions for experiments in such systems.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW B
Publisher:	AMER PHYSICAL SOC
Additional Information:	Copyright for this article belongs to American Physical Society
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	20 Jul 2012 09:28
Last Modified:	20 Jul 2012 09:28
URI:	http://eprints.iisc.ac.in/id/eprint/44824

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