Valley Filtering and Electronic Optics Using Polycrystalline Graphene
Valley Filtering and Electronic Optics Using Polycrystalline Graphene
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DOI：
10.1103/physrevlett.117.247702
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发表时间：
2016-12-09
影响因子：
8.6
通讯作者：
Charlier, J. -C.
中科院分区：
文献类型：
--
作者：
Nguyen, V. Hung;Dechamps, S.;Charlier, J. -C.
在这封信中，从理论上探讨了多晶石墨烯中谷偏振电流的操纵和狄拉克费米子的类光学行为。当施加应变时，由晶界分隔的两个石墨烯域之间的错误取向可能导致它们的电子结构不匹配。这种差异表现为反演对称性的强烈破缺，导致在广泛的传输方向上出现完美的谷偏振。此外，这些石墨烯域充当电子波的不同介质，提供了调制和获得负折射率的可能性。
In this Letter, both the manipulation of valley-polarized currents and the optical-like behaviors of Dirac fermions are theoretically explored in polycrystalline graphene. When strain is applied, the misorientation between two graphene domains separated by a grain boundary can result in a mismatch of their electronic structures. Such a discrepancy manifests itself in a strong breaking of the inversion symmetry, leading to perfect valley polarization in a wide range of transmission directions. In addition, these graphene domains act as different media for electron waves, offering the possibility to modulate and obtain negative refraction indexes.