利用第一性原理研究了两种具有边缘缺陷石墨烯纳米结的自旋输运,即边界氢原子饱和和未被饱和两种情况.结果表明:边缘缺陷改变了电子的输运行为.对于完整的石墨烯纳米带,两种自旋的电子在费米能级附近是完全简并的；对于含有边缘缺陷的石墨烯纳米结,两种自旋的电子在费米能级附近的很大能量范围内表现出自旋分离.电子局域态密度可进一步说明这种输运行为.这些纳米结可产生与自旋相关的极化电流.特别对于未饱和的缺陷结,在任何偏压下都有较高的自旋滤波效率.
First-principles calculation was performed to investigate the transport properties of edge-defect junctions of graphene with H-terminated or bare edges,which were generated by removing edge carbon atoms from a perfect ribbon.The edge defect changes the electronic transport behavior of a zigzag graphene nanoribbon from spin-degenerated for a perfect ribbon to highly spin-polarized for edge-defective ones at the Fermi level.The electronic local density of states isosurface calculations could help understand the transport results.These junctions could generate spin-polatized currents.Especially,the bare edge-defect junction has a high spin filter efficiency regardless of the external bias.This behavior suggests a possible use of the edge-defective graphene in a spin filter system.
参考文献
| [1] | Han MY;Ozyilmaz B;Zhang YB;Kim P .Energy band-gap engineering of graphene nanoribbons[J].Physical review letters,2007(20):6805-1-6805-4-0. |
| [2] | Li X;Wang X;Zhang L;Lee S;Dai H .Chemically derived, ultrasmooth graphene nanoribbon semiconductors.[J].Science,2008(5867):1229-1232. |
| [3] | Miyamoto Y.;Fujita M.;Nakada K. .First-principles study of edge states of H-terminated graphitic ribbons[J].Physical Review.B.Condensed Matter,1999(15):9858-9861. |
| [4] | Lee H;Son Y W;Park N et al.Magnetic ordering at the edges of graphitic fragments:magnetic tail interactions between the edse-localized states[J].Physical Review B:Condensed Matter,2005,72:174431. |
| [5] | Son YW;Cohen ML;Louie SG .Energy gaps in graphene nanoribbons[J].Physical review letters,2006(21):6803-1-6803-4-0. |
| [6] | Barone V;Hod O;Scuseria GE .Electronic structure and stability of semiconducting graphene nanoribbons[J].Nano letters,2006(12):2748-2754. |
| [7] | Abanin DA;Lee PA;Levitov LS .Spin-filtered edge states and quantum hall effect in graphene[J].Physical review letters,2006(17):6803-1-6803-4-0. |
| [8] | Areshkin DA;Gunlycke D;White CT .Ballistic transport in graphene nanostrips in the presence of disorder: Importance of edge effects[J].Nano letters,2007(26):204-210. |
| [9] | Cresti A;Grosso G;Parravicini GP .Numerical study of electronic transport in gated graphene ribbons[J].Physical review, B. Condensed matter and materials physics,2007(20):205433-1-205433-8-0. |
| [10] | Ezawa, M .Peculiar width dependence of the electronic properties of carbon nanoribbons[J].Physical review. B, Condensed Matter And Materials Physics,2006(4):5432-1-5432-8-0. |
| [11] | Gorjizadeh N;Farajian A A;Kawazoe Y .Tbe effects of defects on the conductance of graphene nanoribbons[J].Nanotechnology,2009,20(01):015201. |
| [12] | Topsakal M;Akturk E;Sevincli H;Ciraci S .First-principles approach to monitoring the band gap and magnetic state of a graphene nanoribbon via its vacancies[J].Physical review, B. Condensed matter and materials physics,2008(23):235435-1-235435-6-0. |
| [13] | Ren Yun;Chen Ke-Qiu .Effects of symmetry and Stone-Wales defect on spin-dependent electronic transport in zigzag graphene nanoribbons[J].Journal of Applied Physics,2010,107:044514. |
| [14] | Oeiras R Y;Araújo-Moreira F M;da Silva E Z .Defect-mediated half-metal behavior in zigzag graphene nanoribbons[J].Physical Review B:Condensed Matter,2009,80:073405. |
| [15] | Zheng X H;Rungger I;Zeng Z et al.Effects induced by single and multiple dopants on the transport properties in zigzagedged graphene nanoribbons[J].Physical Review B:Condensed Matter,2009,80:235426. |
| [16] | Zheng X H;Wang R N;Song L L et al.Impurity indnced spin filtering in graphene nanoribbons[J].Applied Physics Letters,2009,95:123109. |
| [17] | Delin A.;Tosatti E.;Weht R. .Magnetism in atomic-size palladium contacts and nanowires - art. no. 057201[J].Physical review letters,2004(5):7201-0. |
| [18] | Castro Neto A H;Guinea F;Novoselov K S et al.Tbe electronic properties of graphene[J].Rev Mod Pays,2009,81:109-162. |
| [19] | Son YW;Cohen ML;Louie SG .Half-metallic graphene nanoribbons[J].Nature,2006(7117):347-349. |
| [20] | Guo J;Gunlycke D;White C T .Field effect on spin-polarized transport in graphene nanoribbons[J].Applied Physics Letters,2008,92:163109. |
| [21] | Zeng M G;Shen L;Yang M et al.Charge and spin transport in graphene-based beterostructure[J].Applied Physics Letters,2011,98:053101. |
| [22] | Gorjizadeh N;Kawazoe Y .Chemical functionalization of graphene nanoribbons[J].J Nanomater,2010,2010:513501. |
| [23] | Kim WY;Kim KS .Prediction of very large values of magnetoresistance in a graphene nanoribbon device[J].Nature nanotechnology,2008(7):408-412. |
| [24] | Kawai T.;Sugino O.;Koga Y.;Miyamoto Y. .Graphitic ribbons without hydrogen-termination: Electronic structures and stabilities[J].Physical Review.B.Condensed Matter,2000(24):R16349-R16352. |
| [25] | Brandbyge M;Mozos J L;Ordejon P et al.Density-functional method for nonequlibrium electron transport[J].Physical Review B:Condensed Matter,2002,65:165401. |
| [26] | Taylor J;Guo H;Wang J .Ab initio modeling of open systems:Charge transfer,electron conduction,and molecular switching of a C60 deviee[J].Physical Review B:Condensed Matter,2001,63:121104. |
| [27] | Martins TB;Miwa RH;da Silva AJR;Fazzio A .Electronic and transport properties of boron-doped graphene nanoribbons[J].Physical review letters,2007(19):6803-1-6803-4-0. |
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