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arXiv · 1001.4667

Symmetry breaking in a localized interacting binary BEC in a bi-chromatic optical lattice

Yongshan Cheng·S. K. Adhikari
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Abstract

By direct numerical simulation of the time-dependent Gross-Pitaevskii equation using the split-step Fourier spectral method we study different aspects of the localization of a cigar-shaped interacting binary (two-component) Bose-Einstein condensate (BEC) in a one-dimensional bi-chromatic quasi-periodic optical-lattice potential, as used in a recent experiment on the localization of a BEC [Roati et al., Nature 453, 895 (2008)]. We consider two types of localized states: (i) when both localized components have a maximum of density at the origin x=0, and (ii) when the first component has a maximum of density and the second a minimum of density at x=0. In the non-interacting case the density profiles are symmetric around x=0. We numerically study the breakdown of this symmetry due to inter-species and intra-species interaction acting on the two components. Where possible, we have compared the numerical results with a time-dependent variational analysis. We also demonstrate the stability of the localized symmetry-broken BEC states under small perturbation.

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Yongshan Cheng, S. K. Adhikari. 2010-01-26. Symmetry breaking in a localized interacting binary BEC in a bi-chromatic optical lattice. https://doi.org/10.1103/physreva.81.023620

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