论文标题
在Lieb光学晶格中的非线性Bloch-Zener振荡
Nonlinear Bloch-Zener oscillations for Bose-Einstein condensates in a Lieb optical lattice
论文作者
论文摘要
我们研究了Lieb光学晶格中Bose-Einstein冷凝物（BEC）的Bloch-Zener振荡和平均场Bloch带。我们发现原子相互作用将打破系统的点组对称性，从而导致狄拉克锥体结构的破坏，而平面谱带则保留在高度对称的线上。由于非线性效应，系统中将出现带有平坦带的管状条带结构。此外，与紧密结合（TB）模型相比，无法描述蜂窝晶格中的相互作用的骨气系统，我们表明TB模型适用于研究Lieb晶格的非线性能量带结构。此外，我们表明循环结构可以通过观察Bloch-Zener振荡中状态的混乱来确定。
We investigate Bloch-Zener oscillations and mean-field Bloch bands of a Bose-Einstein condensate (BEC) in a Lieb optical lattice. We find that the atomic interaction will break the point group symmetry of the system, leading to the destruction of the Dirac cone structure, while the flat band is preserved on the highly symmetric lines. Due to the nonlinear effect, a tubular band structure with a flat band will appear in the system. Furthermore, comparing with that the tight-binding (TB) model fails to describe the interacting bosonic systems in the honeycomb lattice, we show that the TB model is applicable to study the nonlinear energy band structures for the Lieb lattice. In addition, we show that the loop structure can be determined by the observation of the chaos of the state in the Bloch-Zener oscillations.
