凝聚态所学术报告
报告题目: Generation of edge states at an armchair-graphene open boundary and nanoribbons
报告人：朱仲夏 教授
台湾新竹交通大学电子物理系
地点： 物理楼1楼会议室111
时间： 2012年10月26日(星期五) 下午1:30
摘要：We demonstrated that edge states can be generated by an edge-potential at an armchair-graphene open boundary. The edge states are shown not of the same physical origin as the Tamm states in semiconductors. Pseudospin flipping is found to be the key process leading to the formation of these edge states. At an open boundary, the edge potential is shown to turn on pseudospin-flipped (intravalley) scattering even though there is no obvious breaking of the AB site (basis atoms) symmetry. For a valley-polarized incident beam, the interference between the pseudospin-conserving (intervalley) and nonconserving (intravalley) processes lead to a finite out-of-plane pseudospin density. This same mechanism leads to the edge state formation in the evanescent regime. Discussion will also cover armchair-graphene nanoribbon on the energy gap opening and the conductance.
Ref. C.H. Chiu and C.S. Chu, Phys. Rev. B 85, 155444 (2012)
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