• 文献标题:   Dirac fermion metagratings in graphene
  • 文献类型:   Article
  • 作  者:   WAN PC, REN YH, WANG QJ, HUANG D, ZHOU L, GUO HQ, DU JJ
  • 作者关键词:  
  • 出版物名称:   NPJ 2D MATERIALS APPLICATIONS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   7
  • DOI:   10.1038/s41699-021-00222-3
  • 出版年:   2021

▎ 摘  要

We theoretically demonstrate a Dirac fermion metagrating which is an artificially engineered material in graphene. Although its physics mechanism is different from that of optical metagrating, both of them can deliver waves to one desired diffraction order. Here we design the metagrating as a linear array of bias-tunable quantum dots to engineer electron beams to travel along the -1st-order transmission direction with unity efficiency. Equivalently, electron waves are deflected by an arbitrary large-angle ranging from 90 degrees to 180 degrees by controlling the bias. The propagation direction changes abruptly without the necessity of a large transition distance. This effect is irrelevant to complete band gaps and thus the advantages of graphene with high mobility are not destroyed. This can be attributed to the whispering-gallery modes, which evolve with the angle of incidence to completely suppress the other diffraction orders supported by the metagrating and produce unity-efficiency beam deflection by enhancing the -1st transmitted diffraction order. The concept of Dirac fermion metagratings opens up a new paradigm in electron beam steering and could be applied to achieve two-dimensional electronic holography.