Polaritonic solitons in a Bose-Einstein condensate trapped in a soft optical lattice.
Polaritonic solitons in a Bose-Einstein condensate trapped in a soft optical lattice.
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DOI：
10.1103/physrevlett.110.250401
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发表时间：
2013-05
影响因子：
8.6
通讯作者：
G. Dong;Jiang Zhu;Wei-ping Zhang;B. Malomed
中科院分区：
文献类型：
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作者：
G. Dong;Jiang Zhu;Wei-ping Zhang;B. Malomed
本文研究了被困在软一维光学晶格（OL）中的无碰撞玻色-爱因斯坦凝聚体（BEC）的基态（GS），该晶格是由两个反向传播的光束通过局域场效应（LFE）受到BEC密度分布的扰动而形成的。我们发现，LFE会产生包络变形势、相变形引起的非局部势和冷凝物的有效自相互作用。结果，稳定的光子原子（极化）晶格孤子，包括光学分量，以软OL的变形形式，与局域物质波分量相结合，在蓝色失谐设置中产生，没有原子之间的任何直接相互作用。这些自捕获模式实现了系统的GS，与由OL势相互作用和原子间碰撞相互作用支持的间隙孤子有本质上的不同。随着BEC中原子数的增加，从松散束缚模式向紧密束缚模式转变。
We investigate the ground state (GS) of a collisionless Bose-Einstein condensate (BEC) trapped in a soft one-dimensional optical lattice (OL), which is formed by two counterpropagating optical beams perturbed by the BEC density profile through the local-field effect (LFE). We show that LFE gives rise to an envelope-deformation potential, a nonlocal potential resulting from the phase deformation, and an effective self-interaction of the condensate. As a result, stable photon-atomic (polaritonic) lattice solitons, including an optical component, in the form of the deformation of the soft OL, in a combination with a localized matter-wave component, are generated in the blue-detuned setting, without any direct interaction between atoms. These self-trapped modes, which realize the system's GS, are essentially different from the gap solitons supported by the interplay of the OL potential and collisional interactions between atoms. A transition to tightly bound modes from loosely bound ones occurs with the increase of the number of atoms in the BEC.