Electronic Structure of Iridium Clusters on Graphene

ORAL

Abstract

Graphene was predicted to exhibit non-trivial Z2 topology, but its exceedingly weak spin-orbit coupling prevented this from being observed. Previous theoretical work has proposed enhancing the spin-orbit coupling strength by depositing individual adatoms adsorbed onto the surface of graphene. We show experimental evidence that the iridium adatoms cluster, with a cluster size of at least two atoms. We investigate through theoretical calculations the orientation of the iridium dimers on graphene, contrast the electronic structure of iridium dimers with iridium monomers, and compare the theoretical iridium dimer electronic structure calculations with the experimental results determined via scanning tunneling spectroscopy.

*This work was supported by NSF grant No. DMR10-1006184 and U.S. DOE under Contract No. DE-AC02-05CH11231. Computational resources have been provided by DOE at LBNL's NERSC facility.

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Authors

  • Bradford A. Barker

    • University of California - Berkeley, Lawrence Berkeley National Laboratory

  • Aaron J. Bradley

    • Univ of California - Berkeley

  • Miguel M. Ugeda

    • University of California - Berkeley

  • Sinisa Coh

    • University of California - Berkeley, Lawrence Berkeley National Laboratory

  • Alex Zettl

    • University of California - Berkeley, Lawrence Berkeley National Laboratory

  • Michael F. Crommie

    • University of California - Berkeley, Lawrence Berkeley National Laboratory

  • Marvin L. Cohen

    • University of California - Berkeley, Lawrence Berkeley National Laboratory

  • Steven G. Louie

    • University of California - Berkeley, Lawrence Berkeley National Laboratory