【摘要】 研究了自旋依赖双层方形光晶格中玻色-爱因斯坦凝聚体(Bose-Einstein condensates,BEC)的基态特征.双层晶格间的相对扭曲角度和层间耦合强度是影响超冷原子密度分布的重要可调参数.当光晶格的最低能带呈单阱色散时,超冷原子在莫尔晶格(Moire lattice)中的局域化受扭曲角度、层间耦合强度、原子数和晶格深度等的影响;当光晶格的最低能带呈双阱色散时,光晶格的扭曲可导致2个自旋态的反向扭曲,随着层间耦合强度的增加,2个扭曲的自旋态逐渐重合.该研究工作有助于深入探索扭曲光晶格超冷原子中的新奇量子效应.更多还原

【Abstract】 The characteristics of the ground states of Bose-Einstein condensates(BEC) in spin-dependent bilayer square optical lattices are investigated in this paper.The relative twist angle between the two lattices and the interlayer coupling strength are the main tunable parameters that affect the density distribution of the ultracold atoms.When the lowest band of the lattices exhibits a single-well dispersion,the localization of the ultracold atoms in the Moire lattice can be determined from the twist angle,interlayer coupling strength,number of atoms,and lattice depth.When the lowest band of the lattices exhibits a double-well dispersion,the twist between the lattices leads to the twist of the two spin states.With an increase in interlayer coupling strength,the two twisted spin states will overlap.The results of this work will stimulate further exploration of novel quantum effect with ultracold atoms in twisted optical lattices.更多还原