7003全讯入口“博约学术论坛”系列报告
第96期     (2015年第2期)

Title：Edge reconstructions in fractional quantum Hall effect and quantum spin Hall effect
报告人：王建辉 博士（以色列，本-古里安大学）
时   间：2015年1月9日（周五）上午10：00；
地   点：中心教学楼610

ABSTRACT
In the first half of my talk I will discuss edge reconstruction in fractional quantum Hall effect, using the state at filling factor 2/3 as an example. By edge reconstruction we mean the appearance of an additional incompressible strip outside the minimum edge structure when the confining potential is smooth. I will explain how this combined with interaction and disorder provides a unified theory for some recent experimental results, namely a plateau at a transmission of 1/2 through a quantum point contact and a crossover of the effective charge from e/3 at high temperature to 2e/3 at low temperature.
In the second half of my talk I will discuss the edge structure of quantum spin Hall effect when interaction and smoothness of the confining potential are taken into account. Using the Hartree-Fock approximation and exact diagonalization, we find that edge reconstruction is possible for both the Bernevig-Zhang model and the Bernevig-Hughes-Zhang model. The main experimental implication of this is that since the time-reversal symmetry is spontaneously broken, the edge modes are no longer protected and can be completely gapped out or localized.

报告人简历：

王建辉，男，1982年生于北京，2001-2005年在北京大学物理系本科学习，2005年获学士学位，2005-2010年在印地安那大学物理系学习，2010年获博士学位。2010.11-2012.10 在以色列魏兹曼研究所凝聚态物理系，2012.10-2014.9在以色列本-古里安大学物理系分别从事博士后研究。研究兴趣为凝聚态理论，主要研究低维量子系统，特别是电子相互作用导致的现象。
联系方式：7003全讯入口办公室 （68913163）
邀 请 人：姚裕贵 教授
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