基于石墨烯块材料的谷过滤器+-浙江师范大学.PDF

第 36 卷第4 期 浙江师范大学学报（自然科学版） . Vol. 36 ，No. 4 2013 年 11 月 Journal of Zhejiang Normal University ( Nat. Sci.) Nov. 2013 文章编号：1001-5051 (2013) 04-0386-06 基于石墨烯块材料的谷过滤器+ 翟 峰 ， 汪 娟 (浙江师范大学数理与信息工程学 院，浙 江 金 华 321004) 摘 要 :综述了石墨烯谷电子学的部分研究进展;探讨了在二端石墨烯块材料中产生谷 化电流的可能性.在 块材料中，有2 种与谷自由度直接耦合的势能:应变产生的赝矢量势和依赖于子晶格的静电势 交（错势能）. 对称性 析表明，仅靠这2 种势能的作用不能产生谷 化的输出电流.若将这2 种势能 别和普通的磁电垒 联合，就能获得显著的谷过滤效应.利用交错势能和磁电垒联合调制产生的谷电流可通过逆谷Hall效应测 量. 关键词:石墨烯;谷电子学;谷过滤器;应变;交错势能 中图分类号:0488; 0484 文献标识码:A Valley filters based on bulk, graphene ZHAIFeng, W A N G Juan (College of Mathematics, Physics and Information Engineering, Zhejiang Normal University, Jinhua Zhejiang 321004 , China) Abstract ： It was reviewed some progresses in graphene valleytronics. The feasibility of generating a valley-po­ larized current in two-terminal bulk graphene systems was discussed. It was showed that there existed two kinds of potentials coupling directly with the valley degree of freedom ： strain-induced pseudo vector potential and sublattice-dependent electrostatic potential ( staggered potential). It was found from the symmetry analysis that the two potentials alone could not produce a valley polarization in the output current. It was also found that remarkable valley filtering could be achieved when electrons in bulk graphene were modulated by the com­ bination of a conventional magnetic -electric barrier with either of the two potentials. The valley current ob­ tained from tte combination of a staggered potential and a magnetic -electric barrier could be detected by means of ite inverse valley Hall effect. Key words ： graphene; valleytronics; valley filter; strain; staggered potential 0