Focusing of electron flow in a bipolar graphene ribbon with different chiralities

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	Focusing of electron flow in a bipolar graphene ribbon with different chiralities
	Xing, YX ; Wang, J ; Sun, QF
刊名	PHYSICAL REVIEW B
	2010
卷号	81 期号:16
关键词	SURFACE-BAND CALCULATIONS BERRYS PHASE BILAYER GRAPHENE SIMPLE SCHEME LENS
ISSN号	1098-0121
通讯作者	Xing, YX: Univ Hong Kong, Dept Phys, Pokfulam Rd, Hong Kong, Hong Kong, Peoples R China.
中文摘要	The focusing of electron flow in a symmetric p-n junction (PNJ) of graphene ribbon with different chiralities is studied. Considering the PNJ with the sharp interface, in a armchair ribbon, the electron flow emitting from (-L, 0) in n region can always be focused perfectly at (L, 0) in p region in the whole Dirac fermion regime, i.e., in whole regime E(0) < t, where E(0) is the distance between Dirac-point energy and Fermi energy and t is the nearest hopping energy. For the bipolar ribbon with zigzag edge, however, the incoming electron flow in n region is perfectly converged in p region only in a very low energy regime with E(0) < 0.05t. Moreover, for a smooth PNJ, electrons are backscattered near PNJ, which weakens the focusing effect. But the focusing pattern still remains the same as that of the sharp PNJ. In addition, quantum oscillation in charge density occurs due to the interference between forward and backward scatterings. Finally, in the presence of weak perpendicular magnetic field, charge carriers are deflected in opposite directions in the p region and n region. As a result, the focusing effect is smeared. The lower the energy E0, the easier the focusing effect is destroyed. For the high-energy E(0) (e.g., E(0) = 0.9t), however, the focusing effect can still survive in a moderate magnetic field on order of 1 T.
收录类别	SCI
资助信息	Government of HKSAR [HKU 704308P]; NSF-China [10734110, 10821403, 10974236]
语种	英语
公开日期	2013-09-17
内容类型	期刊论文
源URL	[http://ir.iphy.ac.cn/handle/311004/38326]
专题	物理研究所_物理所公开发表论文_物理所公开发表论文_期刊论文
推荐引用方式 GB/T 7714	Xing, YX,Wang, J,Sun, QF. Focusing of electron flow in a bipolar graphene ribbon with different chiralities[J]. PHYSICAL REVIEW B,2010,81(16).
APA	Xing, YX,Wang, J,&Sun, QF.(2010).Focusing of electron flow in a bipolar graphene ribbon with different chiralities.PHYSICAL REVIEW B,81(16).
MLA	Xing, YX,et al."Focusing of electron flow in a bipolar graphene ribbon with different chiralities".PHYSICAL REVIEW B 81.16(2010).