Fallani L, Cataliotti F S, Catani J, Fort C, Modugno M, Zawada M, Inguscio M
European Laboratory for Non-Linear Spectroscopy (LENS), INFM and Dipartimento di Fisica, Università di Firenze, via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy.
Phys Rev Lett. 2003 Dec 12;91(24):240405. doi: 10.1103/PhysRevLett.91.240405. Epub 2003 Dec 10.
We report the experimental observation of a lensing effect on a Bose-Einstein condensate expanding in a moving 1D optical lattice. The effect of the periodic potential can be described by an effective mass dependent on the condensate quasimomentum. By changing the velocity of the atoms in the frame of the optical lattice, we induce a focusing of the condensate along the lattice direction. The experimental results are compared with the numerical predictions of an effective 1D theoretical model. In addition, a precise band spectroscopy of the system is carried out by looking at the real-space propagation of the atomic wave packet in the optical lattice.
我们报告了对在移动的一维光学晶格中膨胀的玻色-爱因斯坦凝聚体的透镜效应的实验观察。周期势的效应可以用一个依赖于凝聚体准动量的有效质量来描述。通过改变光学晶格框架中原子的速度，我们诱导凝聚体沿晶格方向聚焦。将实验结果与一维有效理论模型的数值预测进行了比较。此外，通过观察原子波包在光学晶格中的实空间传播，对该系统进行了精确的能带光谱分析。
