We study dynamical behaviors of the weakly interacting Bose–Einstein condensate in the onedimensional optical lattice with an overall double-well potential by solving the time-dependent Gross–Pitaevskii equation. It is observed that the double-well potential dominates the dynamics of such a system even if the lattice depth is several times larger than the height of the double-well potential. This result suggests that the condensate flows without resistance in the periodic lattice just like the case of a single particle moving in periodic potentials. Nevertheless, the effective mass of atoms is increased, which can be experimentally verified since it is connected to the Josephson oscillation frequency. Moreover, the periodic lattice enhances the nonlinearity of the double-well condensate, making the condensate more “self-trapped” in the π -mode self-trapping regime.
. Dynamics of Bose–Einstein condensates in a one-dimensional optical lattice with double-well potential[J]. Frontiers of Physics, 2013, 8(4): 375-380.
Han-Lei Zheng, Qiang Gu. Dynamics of Bose–Einstein condensates in a one-dimensional optical lattice with double-well potential. Front. Phys. , 2013, 8(4): 375-380.
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The lattice will be more perfect if it consists of more lattice sites. We choose k= 7 in order to show the lattice feature clearly in figures.
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