报告题目:  Collective modes in a spherical Bose-Einstein condensate
报 告 人:  江开军 研究员
时    间： 1月 19日（星期五）上午 9:30~10:30
地    点：3-323

报告摘要：

Collective mode plays an important role in describing the many-body correlation in the condensed matter and ultracold quantum gasses. Understanding its decaying process can help reveal the intrinsic loss mechanics of the many-body correlation in the macroscopic quantum systems. In an anisotroptic system, studying this decaying process is difficult due to the complex coupling channels with the background particles. In this work, we produce a spherical Bose-Einstein condensate in an optical dipole trap, in which the collective-mode spectra were simplified. We have experimentally studied the decaying processes of collective modes in the spherical Bose-Einstein condensate and the prediction based on the Bogliubov perturbation theory has a good agreement. The Landau damping for the coupling between the elementary mode and the heat excitations varies from tens of to more than one hundred microseconds, dependent on the excitation symmetry. We have also observed the Beliaev damping process where the high-energy mode is coupled to the low-energy mode, in a manner analogous to the parametric down-conversion of light in a nonlinear media.

报告人简介：

江开军，中科院武汉物理与数学研究所研究员，博士生导师，中科院“百人计划”入选者。1998年于武汉大学获得学士学位，2005年于中科院武汉物理与数学研究所获博士学位，2005-2010年在美国国家标准与技术研究院(NIST)和法国巴黎高等师范学院(ENS)从事博士后研究，2010年回国工作。主要从事超冷原子物理研究，先后在Nature, Physical Review Letters等国际期刊上发表文章40多篇，文章被SCI期刊引用800多次。先后承担国家基金委面上、重大研究计划、重点项目和国家科技部重点研发计划等国家重要项目。研究方向：超冷量子气体中的集体关联效应，超冷原子中的新奇量子态，利用超冷原子从事量子模拟和精密测量研究。