论文标题
玻色子的相互作用增强的组速度在光学Kagome晶格的平坦带中
Interaction-Enhanced Group Velocity of Bosons in the Flat Band of an Optical Kagome Lattice
论文作者
论文摘要
kagome晶格中粒子运动的几何挫折导致单粒子带结构具有平坦的S轨带。我们通过刺激玻色网凝结物进入光学kagome晶格的激发蓝色状态，然后通过原子动量分布来测量组速度来探测这种带的结构。我们发现，相互作用重新归一化的是kagome晶格的频带结构，大大增加了第三个频段的分散体，根据非交互带理论，该频段几乎应该是非分散的。各种晶格深度和气体密度的测量值与晶格总岩体方程的预测一致，这表明所观察到的频带结构的变形是由相互作用通过相互作用远离Kagome几何形状的整体晶格潜力引起的。
Geometric frustration of particle motion in a kagome lattice causes the single-particle band structure to have a flat s-orbital band. We probe this band structure by exciting a Bose-Einstein condensate into excited Bloch states of an optical kagome lattice, and then measuring the group velocity through the atomic momentum distribution. We find that interactions renormalize the band structure of the kagome lattice, greatly increasing the dispersion of the third band that, according to non-interacting band theory, should be nearly non-dispersing. Measurements at various lattice depths and gas densities agree quantitatively with predictions of the lattice Gross-Pitaevskii equation, indicating that the observed distortion of band structure is caused by the disortion of the overall lattice potential away from the kagome geometry by interactions.
