Nonlinear Effect in Parity-Time Symmetric Periodic Potentials

主讲人 (Speaker): 
张永平
主讲人单位 (Speaker's Institute): 
上海大学
邀请人 (Invited by): 
李朝红
时间 (Time): 
星期一, 2018/10/08 - 10:30 to 11:30
地点 (Location): 
珠海校区海滨红楼17栋206 (Rm 206, Red House 17)
摘要 (Abstract): 

      Parity-time symmetric non-Hermitian systems have attracted lots of recent research attention. One of such kinds of fundamental systems is parity-time symmetric periodic potentials, which have been implemented recently in atomic and photonic optics. In these systems, nonlinearity effect enriches relevant physics.  It has been investigated that nonlinearity has an interesting effect on parity-time phase transition. However, in their study, the nonlinearity is not strong enough in comparison with potential depth. Here, I will show that if the nonlinearity dominates over lattice potentials, loop structures appear in nonlinear Bloch bands. Such loops demonstrate interesting properties in the presence of parity-time symmetric lattices.  Furthermore, the loops contribute to the protection of parity-time phase transition.

主讲人简介 (Speaker's CV): 
张永平主要从事超冷原子物理的理论研究,目前的研究内容为冷原子系统,特别是含有自旋轨道耦合的冷原子系统中的非线性现象。 在这个研究方向上,同美国华盛顿州立大学的Peter Engels教授领导的实验组有长期实质性的合作。已经发表SCI论文30多篇,其中第一作者的文章Phys.Rev.Lett.108,035301(2012)引用超过140次,被Web of Science选为高被引论文。现在主持的人才类项目包括青年千人计划、上海市“东方学者 ”和上海市“曙光学者”。