• 文献标题:   Scale-invariant large nonlocality in polycrystalline graphene
  • 文献类型:   Article
  • 作  者:   RIBEIRO M, POWER SR, ROCHE S, HUESO LE, CASANOVA F
  • 作者关键词:  
  • 出版物名称:   NATURE COMMUNICATIONS
  • ISSN:   2041-1723
  • 通讯作者地址:   CIC NanoGUNE
  • 被引频次:   6
  • DOI:   10.1038/s41467-017-02346-x
  • 出版年:   2017

▎ 摘  要

The observation of large nonlocal resistances near the Dirac point in graphene has been related to a variety of intrinsic Hall effects, where the spin or valley degrees of freedom are controlled by symmetry breaking mechanisms. Engineering strong spin or valley Hall signals on scalable graphene devices could stimulate further practical developments of spin-and valleytronics. Here we report on scale-invariant nonlocal transport in large-scale chemical vapor deposition graphene under an applied external magnetic field. Contrary to previously reported Zeeman spin Hall effect, our results are explained by field-induced spin-filtered edge states whose sensitivity to grain boundaries manifests in the nonlocal resistance. This phenomenon, related to the emergence of the quantum Hall regime, persists up to the millimeter scale, showing that polycrystalline morphology can be imprinted in nonlocal transport. This suggests that topological Hall effects in large-scale graphene materials are highly sensitive to the underlying structural morphology, limiting practical realizations.