Trapped Bose-Einstein condensates with attractive s-wave interactions

报告题目：Trapped Bose-Einstein condensates with attractive s-wave interactions

报 告 人：易俗 研究员（中科院理论物理研究所）

时    间：2019年11月12日（周二）上午10:30  

地    点：LE523   

邀 请 人：胡自翔   

报告摘要：

Within the framework of the Gaussian-state theory, we show that the quantum many-body ground state of a trapped condensate with weakly attractive interaction is a single-mode squeezed vacuum state, as oppose to the coherent state under repulsive interaction. The spatial mode of the squeezed-state condensates satisfies a Gross-Pitaevskii like equation in which the interaction strength is augmented by a factor $3$ due to the large particle fluctuation of the squeezed state. We also study the collective excitations of the condensates by the tangential space projection, which leads to new two-particle excitations and confirms the phase transition from coherent-state to squeezed-state condensates. Our investigation clarifies the quantum states of the attractive condensates and will shed new light on research of the droplet phases in dipolar and multicomponent condensates.

报告人简介：

易俗：本硕毕业于中国科技大学力学和机械工程系，美国佐治亚理工大学理论物理博士，先后在佐治亚理工大学，Rice大学进行博士后研究，2005年起任职于中国科学院理论物理研究所，研究员。国家杰出青年基金，中国科学院百人计划获得者。研究方向为原子分子物理和光学；量子物理与量子信息等。在PRL，PRA/B, NJP等期刊发表近百篇论文，其中PRL12篇。