Topological Band Engineering Graphene Nanoribbons

ORAL

Abstract

Graphene nanoribbons (GNRs) are 1-dimensional semiconducting strips of graphene that possess novel electronic and magnetic properties. The atomic precision afforded by recent bottom-up synthetic techniques has led to a surge in tailor-made GNR structures whose physical properties can be controllably tuned through modification of width, edge chirality, and dopant incorporation. Recent theoretical work reveals the presence of non-trivial topological phases in GNRs, and correspondingly, the existence of zero-energy symmetry-protected topological interface states. Using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS), we investigate the first experimental realization of controlled heterojunctions composed of two topologically distinct GNR classes. Our approach enables us to create a periodic superlattice of topological interface states, whose bonding/anti-bonding interactions lead to the creation of two new frontier bands. This yields a drastically reduced band gap compared to either of the two constituent GNRs, revealing the powerful role topology will play in engineering new GNR electronic structures.

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Presenters

  • Daniel Rizzo

    Physics, University of California - Berkeley

Authors

  • Daniel Rizzo

    Physics, University of California - Berkeley

  • Greg Veber

    Chemistry, University of California - Berkeley

  • Ting Cao

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

  • Christopher Bronner

    Physics, University of California - Berkeley

  • Henry Rodriguez

    Physics, University of California - Berkeley

  • Steven Louie

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

  • Michael Crommie

    Physics, Univ of California - Berkeley, UC Berkeley and LBNL, Univ of California - Berkeley, UCB, Physics, UC Berkeley, Physics, University of California, Berkeley, Department of physics, University of California - Berkeley, Physics, University of California - Berkeley

  • Felix Fisher

    Chemistry, UC Berkeley, Chemistry, University of California - Berkeley