Carusotto I, Hu S X, Collins L A, Smerzi A
CNR-BEC-INFM, Trento, I-38050 Povo, Italy.
Phys Rev Lett. 2006 Dec 31;97(26):260403. doi: 10.1103/PhysRevLett.97.260403. Epub 2006 Dec 27.
We study the density modulation that appears in a Bose-Einstein condensate flowing with supersonic velocity against an obstacle. The experimental density profiles observed at JILA are reproduced by a numerical integration of the Gross-Pitaevskii equation and then interpreted in terms of Cerenkov emission of Bogoliubov excitations by the defect. The phonon and the single-particle regions of the Bogoliubov spectrum are, respectively, responsible for a conical wave front and a fan-shaped series of precursors.
我们研究了在玻色-爱因斯坦凝聚体以超音速流向障碍物时出现的密度调制。通过对格罗斯-皮塔耶夫斯基方程进行数值积分，再现了在JILA观测到的实验密度分布，然后根据缺陷对玻戈留波夫激发的切伦科夫辐射进行了解释。玻戈留波夫谱的声子区域和单粒子区域分别对应一个锥形波前和一系列扇形的前驱波。
