题目：Composite fermion Fermi sea: Is the glass half empty or half full? 

　　时间：下周一（19日）上午10:00点 

　　地点：强磁场五楼大会议室 

　　报告人：Jainendra K. Jain教授（宾州州立大学） 

　　摘要： 

　　Composite fermions are emergent topological particles that arise as a result of interaction between electrons confined to two dimensions and exposed to a strong magnetic field. They were postulated to explain the phenomenon of the fractional quantum Hall effect as the integer quantum Hall effect of composite fermions. After a brief pedagogical introduction, I will come to some recent puzzles regarding a remarkable manifestation of composite fermions at the half filled Landau level, namely their Fermi sea, which arises as a non-perturbativeconsequence of emergent gauge fields in a system where there was no Fermi sea to begin with. An intuitive picture suggests two equally plausible Fermi seas that appear to be topologically distinct and occupy different areas. We provide theoretical evidence that these are in fact dual descriptions of the same state. We calculate the Fermi wave vector in a particle- hole symmetric theory, and find our results to be generally consistent with the experimental results of Kamburov et al. [Phys. Rev. Lett. 113, 196801 (2014)]. Most remarkably, we predict that the area of the CF Fermi sea slightly violates the cherished Luttinger‘s area rule of Fermi liquids. This work [A. C. Balram and C. Toke arXiv:1506.02747 (2015) and Phys. Rev. Lett. in press] was supported by the US Department of Energy. 

　　报告人简介： 

　　JAINENDRA JAIN received Ph.D. degree from Stony Brook University (1985). After postdoctoral work at the University of Maryland and the Yale University, he joined the Stony Brook University as a faculty in 1989, and then moved to Penn State in 1998.  

　　Jain is a theoretical physicist interested in unexpected quantum mechanical reorganizations that occur when a large number of particles interact, best known for work leading to the discovery of exotic particles called “composite fermions,” which he had postulated to explain the fractional quantum Hall effect. For this work, Jain was a co-recipient of the American Physical Society’s Oliver E. Buckley Prize in 2002. Jain has received several other Fellowships and awards. He is currently the Evan Pugh University Professor and Erwin W. Mueller Professor at Penn State, and also holds the Raman Visiting Chair and Infosys Visiting Chair Professorships in India.