报告题目 (Title)：The miscible-immiscible transition of quasi Bose-Einstein condensates and Tonks-Girardeau gas mixture in 1D（准一维玻色爱因斯坦凝聚与TG气体混合物的混融与分离的相变）

报告人 (Speaker)：贺文斌 博士后（冲绳科学技术大学）

报告时间 (Time)：2024年8月26日(周一) 14:30-16:30

报告地点 (Place)：校本部 G313

邀请人 (Inviter)：张永平 教授

主办部门：量子科技研究院/理学院物理系

摘要 (Abstract)：

We studied the quantum mixture of quasi Bose-Einstein condensates (BEC) and Tonks-Girardeau (TG) gas mixture in 1D. The density distribution of BEC and TG show cutting jump with varying with interspecies repulsive interaction, hence a phase separation (PS) transition. Then we looked at the energy of the mixture, it shows the energy of BEC and TG firstly linear increase with repulsion then almost saturate. While interaction energy suddenly jump down to zero after repulsion crossing critical point. We also applied mean field (MF) method to study the PS, which support above results qualitatively. However it shows that the critical point is beyond the MF method's description, while the occupation length of BEC by MF agrees with exact numeric'. Finally, we mapped out the phase diagram of the quantum mixture by using density covariance as order parameter. It's hopeful to observe the results of the work in ultracold atom platform since TG gas and BEC are common ingredient of the experiment.