光学Kagome晶格平带中玻色子的相互作用增强群速度
Interaction-Enhanced Group Velocity of Bosons in the Flat Band of an Optical Kagome Lattice
摘要：
粒子在可果美晶格中运动的几何阻挫导致单粒子能带结构具有平坦的s轨道带。我们通过激发一个玻色-爱因斯坦凝聚体进入光格点的激发布洛赫态，然后通过原子动量分布测量群速度来探测这种能带结构。我们发现，相互作用重整化的能带结构的戈薇晶格，大大增加了第三带的色散，根据非相互作用带理论，应该是近非色散。在不同的晶格深度和气体密度的测量同意定量与晶格Gross-Pitaevskii方程的预测，表明所观察到的能带结构的畸变是由整体晶格势的畸变远离kagome几何的相互作用。
英文摘要：
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.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
