题  目：Dephasing effect on backscattering of helical surface states in 3D topological insulators

报告人：刘海文博士 北京大学量子材料中心

时  间：11月17日（星期一）上午10：00

地  点：理科二号楼B409

报告摘要：We analyze the dephasing effect on the backscattering behavior of the helical surface states in 3D topological insulators. Considering the dilute non-magnetic impurities condition, we calculate the second-order scattering amplitude and the backscattering cross-section for both short-range and long-range scattering potentials. Our results indicate the combination effect of dephasing and scattering can cause backscattering in the helical SS, although one of them can not alone. In specific, the long-range Coulomb potential can cause extremely large backscattering when energy is close to the Dirac point. This large backscattering can lead to the anomalous ‘‘gap-like’’ features observed in recent experiments [Nat. Phys. 7, 840(2011)].

报告人简介：刘海文，2006年北京大学伟德betvlctor体育官网毕业，2012年获中国科学院物理研究所理学博士。2012年7月至今在北京大学量子材料中心从事博士后研究工作。发表SCI文章15篇，其中3篇Phys. Rev. Lett., 1篇Nano. Lett.。近期研究方向为低维体系中的拓扑效应和超导现象。

Host: Dr. Juntao Song

Email: jtsong@hebtu.edu.cn