• 文献标题:   Spin Hall Effect and Origins of Nonlocal Resistance in Adatom-Decorated Graphene
  • 文献类型:   Article
  • 作  者:   VAN TUAN D, MARMOLEJOTEJADA JM, WAINTAL X, NIKOLIC BK, VALENZUELA SO, ROCHE S
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   Univ Delaware
  • 被引频次:   29
  • DOI:   10.1103/PhysRevLett.117.176602
  • 出版年:   2016

▎ 摘  要

Recent experiments reporting an unexpectedly large spin Hall effect (SHE) in graphene decorated with adatoms have raised a fierce controversy. We apply numerically exact Kubo and Landauer-Bttiker formulas to realistic models of gold-decorated disordered graphene (including adatom clustering) to obtain the spin Hall conductivity and spin Hall angle, as well as the nonlocal resistance as a quantity accessible to experiments. Large spin Hall angles of similar to 0.1 are obtained at zero temperature, but their dependence on adatom clustering differs from the predictions of semiclassical transport theories. Furthermore, we find multiple background contributions to the nonlocal resistance, some of which are unrelated to the SHE or any other spin-dependent origin, as well as a strong suppression of the SHE at room temperature. This motivates us to design a multiterminal graphene geometry which suppresses these background contributions and could, therefore, quantify the upper limit for spin-current generation in two-dimensional materials.