Controlling in-gap states in graphene nanoribbons via tunable topological phases

ORAL

Abstract

Graphene nanoribbons (GNRs) possess distinct symmetry-protected electron topological phases that depend on structure and termination. We show, through first-principles calculations, that by applying an experimentally accessible transverse electric field, certain designer GNRs may be tuned from a topologically trivial to a nontrivial phase or vice versa. With a spatially varying field, junctions of GNRs with distinct topological phases can be created, with localized topological in-gap interface states emerging at these junctions. We further study the formation of in-gap end states inside different energy gaps around the Fermi level for a finite GNR segment, including the conditions for end state to emerge in energy gaps other than the charge-neutrality gap. This work is supported by the National Science Foundation and the Office of Naval Research under the Muri Program. Computational resources have been provided by DOE at Lawrence Berkeley National Laboratory's NERSC facility.

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Presenters

  • Fangzhou Zhao

    • University of California, Berkeley

Authors

  • Fangzhou Zhao

    • University of California, Berkeley

  • Steven Louie

    • University of California at Berkeley, and Lawrence Berkeley National Laboratory
    • Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, C
    • University of California, Berkeley
    • Department of Physics, University of California, Berkeley
    • Lawrence Berkeley National Laboratory and University of California at Berkeley
    • Department of Physics, University of California at Berkeley and Lawrence Berkeley National Laboratory
    • Department of Physics, UC Berkeley
    • Physics, Unviersyt of Calfornia, Berkeley
    • Physics, University of California, Berkeley
    • Physics, University of California, Berkeley and Lawrence Berkeley National Lab