南京大学学报(自然科学版) ›› 2014, Vol. 50 ›› Issue (1): 14.
肖灿俊,董锦明
Xiao Can-Jun, Dong Jin-Ming
摘要: 基于紧束缚近似哈密顿模型,运用波包动力学方法,数值模拟研究了石墨烯电子穿越线缺陷的输运性质和相应的透射率,着重探讨线缺陷对于电子Valley赝自旋的滤波特性。模拟结果表明:1)石墨烯线缺陷对于电子valley赝自旋具有半透性;2)电子的透射率与入射角度和能量都有关;3)在某个临界角度,透射率出现峰值,其大小随着能量的增加而增大,而的绝对值却随能量的增加而减小。4)当入射角大于时,透射率将急剧地降为0。进一步的理论分析指出,这是由于透射率能量关系中的非线性项所造成的。最后,我们的数值模拟结果进一步地证明了石墨烯线缺陷未来作为valley赝自旋滤波器件的实用可能性。
[1] Novoselov K S, Geim A K, Morozov S V, et al., Electric field effect in atomically thin carbon films. Science, 2004, 306 : 666 ~ 669. [2] Geim A K, Novoselov K S. The rise of graphene[J]. Nature Materials, 2007, 6 :183~191. [3] Wolf S A, Awschalom D D, Buhrman R A, et al., Spintronics: a spin-based electronics vision for the future[J]. Science, 2001, 294 :1488~1495. [4] Zutic I, Fabian J, Sarma S Das. Spintronics: Fundamentals and applications[J]. Reviews of Modern Physics, 2004, 76 : 323~410. [5] 唐 涛,曹庆琪,谷坤明 等, La1-xAgxMnO3多晶非均匀颗粒系统的巨磁电阻效应[J].南京大学学报(自然科学),2000,36(4):423~426. [6] Wallace P R. The band theory of graphite[J]. Physical Review, 1947, 71 : 622~634. [7] Neto A H C, Guinea F, Peres N M R, et al., The electronic properties of graphene. Reviews of Modern Physics, 2009, 81 : 109~162. [8] Huang P Y, Ruiz-Vargas C S, van der Zande A M, et al., Grains and grain boundaries in single-layer graphene atomic patchwork quilts[J]. Nature, 2011, 469 : 389~392. [9] Lahiri J, Lin Y, Oleynik I I, et al., An extended defect in graphene as a metallic wire[J]. Nature Nanotechnology, 2010, 5 : 326~329. [10] Yazyev O V, Louie S G. Electronic transport in polycrystalline grapheme[J]. Nature Materials, 2010, 9 : 806~809. [11] Gunlycke D, White C T. Graphene valley filter using a line defect[J]. Physical Review Letters, 2011, 106 : 136806. [12] Jiang L W, Lv X L, Zheng Y S. Valley polarized electronic transport through a line defect in graphene: An analytical approach based on tight-binding model[J]. Physics Letters A, 2011, 376 : 136~141. [13] Wei?e A, Wellein G, Alvermann A, et al., The kernel polynomial method[J]. Reviews of Modern Physics, 2006, 78 : 275~306. [14] Chen R Q, Guo H. The Chebyshev propagator for quantum systems[J]. Computer Physics Communications, 1999, 119 :19~31. |
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