• 文献标题:   Valley filtering by a line-defect in graphene: quantum interference and inversion of the filter effect
  • 文献类型:   Article
  • 作  者:   INGARAMO LH, TORRES LEFF
  • 作者关键词:   graphene, line defect, valley filter, valleytronic
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984 EI 1361-648X
  • 通讯作者地址:   Univ Nacl Cordoba
  • 被引频次:   7
  • DOI:   10.1088/0953-8984/28/48/485302
  • 出版年:   2016

▎ 摘  要

Valley filters are crucial to any device exploiting the valley degree of freedom. By using an atomistic model, we analyze the mechanism leading to the valley filtering produced by a line-defect in graphene and show how it can be inverted by external means. Thanks to a mode decomposition applied to a tight-binding model we can resolve the different transport channels in k-space while keeping a simple but accurate description of the band structure, both close and further away from the Dirac point. This allows the understanding of a destructive interference effect, specifically a Fano resonance or antiresonance located on the p-side of the Dirac point leading to a reduced conductance. We show that in the neighborhood of this feature the valley filtering can be reversed by changing the occupations with a gate voltage, the mechanism is explained in terms of a valley-dependent Fano resonance splitting. Our results open the door for enhanced control of valley transport in graphene-based devices.