报告题目： Symmetry Enriched Bose Einstein Condensation
报 告 人： 龚明 教授 中国科学技术大学量子信息重点实验室
时 间 ： 2017年6月22号（星期四）下午3:00
报告摘要：We consider the fate of Bose-Einstein condensation (BEC) with time-reversal symmetry and inversion symmetry in a spin-orbit coupled bilayer system. When these two symmetry operators commute, all the single particle bands are exactly two-fold degenerate in the momentum space. The scattering in the two-fold degenerate rings can relax the spin-momentum locking effect resulting from spin-orbit coupling, thus we can realize the spin polarized plane wave phase even when the inter-particle interaction dominates. When these two operators anti-commute, the lowest two bands may have the same minimal energy, which have totally different spin structures. As a result, the competition between different condensates in these two energetically degenerate rings can give rise to interesting stripe phases with atoms condensed at two or four colinear momenta. We find that the crossover between these two cases is accompanied by the excited band condensation when the interference energy can overcome the increased single particle energy in the excited band. This effect is not based on strong interaction, thus can be realized even with moderate interaction strength.
报告人简介：龚明，教授、博士生导师。2010年博士毕业于中国科学技术大学，2010 – 2012年在华盛顿州立大学和德州大学达拉斯分校从事博士后研究，2012 – 2015年在香港中文大学担任助理研究教授，2015年到现在在中国科学技术大学量子信息实验室担任教授。主要从事量子计算、量子模拟、拓扑量子计算以及多体物理等方面的研究。在Nature Communications, Phys. Rev. Lett.等杂志上发表论文50多篇。
