Topological Phases in Graphene Nanoribbons

ORAL

Abstract

Using first-principles and model Hamiltonian calculations, we find that the band structures of various graphene nanoribbons give rise to interesting quantized Zak phases, depending on ribbon shape, width and edge termination. The Zak phase, an invariant of the occupied bands of the graphene nanoribbon, identifies the topological phase of the system and dictates the number of end states through the bulk-boundary correspondence. We moreover show that it can be modified by introducing an array of appropriate dopant atoms in the graphene nanoribbons. We demonstrate the origin of these findings, and connect our results to experimental measurements.

*This work is supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division, and by the National Science Foundation. Computational resources have been provided by NERSC at LBNL.

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Authors

  • Ting Cao

    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory

  • Fangzhou Zhao

    • Univ of California - Berkeley
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab

  • Steven G. Louie

    • Department of Physics, UC Berkeley and Lawrence Berkeley National Lab
    • UC Berkeley and Lawrence Berkeley National Lab
    • University of California at Berkeley and Lawrence Berkeley National Lab
    • Physics Department, UC Berkeley and Lawrence Berkeley National Lab
    • Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
    • Univ of California - Berkeley and Lawrence Berkeley National Lab