基于石墨烯块材料的谷过滤器

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极化电流的可能性．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）．对称性分析表明，仅靠这2种势能的作用不能产生谷极化的输出电流．若将这2种势能分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．

Valley filters based on bulk graphene

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 the combination of a staggered potential and a magnetic-electric barrier could be detected by means of the inverse valley Hall effect.