题目：Fractional exclusion and braid statistics in low dimensions
报告人：叶飞 副教授（南方科技大学）
时  间：2017年3月30日(周四)下午2:00
地  点：北京理工大学中心教学楼610
 

摘要：
The statistics of identical particles plays a crucial role in their physical properties, which usually has two aspects: (i) the exchange statistics, which is reflected by the monodromy of the many body wavefunction; and (ii) the exclusion statistics, which is based upon state counting. In three dimensions, there exist only the Fermi and Bose statistics. The antisymmetric (for fermion) and symmetric (for boson) wavefunctions usually imply the Pauli's exclusion statistics and the BEC without exclusion statistics, respectively. In one or two dimensional systems, the braid (fractional exchange) statistics is allowed which interpolates between symmetric and antisymmetric wave functions. The exclusion statistics can also be extended to the fractional case, first proposed by F. D. M. Haldane more than two decades ago, which leads to an intermediate distribution function between the Bose-Einstein and Fermi-Dirac distribution functions. Although at the two ends of statistics, namely, bosons and fermions, the exclusion statistics can be derived from the exchange statistics, but in general the relation between the fractional exchange and exclusion statistics are not clear. In this talk, we present our recent study on the relation between the two fractional statistics in one and two dimensional systems using the Chern-Simons gauge theory and its dimensional reduction form, and show that in some special cases the fractional exchange statistics can induce fractional exclusion statistics.

简历：
叶飞，南方科技大学副教授。本科与博士毕业于上海交通大学物理系。博后毕业于清华大学高等研究中心。曾先后在清华高研、中国科学院大学担任副研究员和副教授。现执教于南方科技大学。研究领域集中在凝聚态理论，包括拓扑绝缘体、分数量子霍尔效应、高温超导理论等。在Phys. Rev. Lett., Phys. Rev. B等国际一流期刊发表论文数篇。
联系方式：物理学院办公室 （68913163）
 

邀请人：杨帆 教授
网    址：http://physics.bit.edu.cn/