Engineering of robust topological quantum phases in graphene nanoribbons

Groning O, Wang S, Yao X, Pignedoli CA, Barin GB, Daniels C, Cupo A, Meunier V, Feng X, Narita A, Muellen K, Ruffieux P, Fasel R (2018)

Publication Type: Journal article

Publication year: 2018

Journal

Nature Nature Research

Book Volume: 560

Pages Range: 209-213

Journal Issue: 7717

DOI: 10.1038/s41586-018-0375-9

Abstract

Boundaries between distinct topological phases of matter support robust, yet exotic quantum states such as spin–momentum locked transport channels or Majorana fermions^1–3. The idea of using such states in spintronic devices or as qubits in quantum information technology is a strong driver of current research in condensed matter physics^4–6. The topological properties of quantum states have helped to explain the conductivity of doped trans-polyacetylene in terms of dispersionless soliton states^7–9. In their seminal paper, Su, Schrieffer and Heeger (SSH) described these exotic quantum states using a one-dimensional tight-binding model^10,11. Because the SSH model describes chiral topological insulators, charge fractionalization and spin–charge separation in one dimension, numerous efforts have been made to realize the SSH Hamiltonian in cold-atom, photonic and acoustic experimental configurations^12–14. It is, however, desirable to rationally engineer topological electronic phases into stable and processable materials to exploit the corresponding quantum states. Here we present a flexible strategy based on atomically precise graphene nanoribbons to design robust nanomaterials exhibiting the valence electronic structures described by the SSH Hamiltonian^15–17. We demonstrate the controlled periodic coupling of topological boundary states¹⁸ at junctions of graphene nanoribbons with armchair edges to create quasi-one-dimensional trivial and non-trivial electronic quantum phases. This strategy has the potential to tune the bandwidth of the topological electronic bands close to the energy scale of proximity-induced spin–orbit coupling¹⁹ or superconductivity²⁰, and may allow the realization of Kitaev-like Hamiltonians³ and Majorana-type end states²¹.

Involved external institutions

Eidgenössische Materialprüfungs- und Forschungsanstalt (Empa) / Swiss Federal Laboratories for Materials Science & Technology

Switzerland (CH) Rensselaer Polytechnic Institute (RPI)

United States (USA) (US) Technische Universität Dresden

Germany (DE) Max-Planck-Institut für Polymerforschung (MPI-P) / Max Planck Institute for Polymer Research

Germany (DE)

How to cite

APA:

Groning, O., Wang, S., Yao, X., Pignedoli, C.A., Barin, G.B., Daniels, C.,... Fasel, R. (2018). Engineering of robust topological quantum phases in graphene nanoribbons. Nature, 560(7717), 209-213. https://doi.org/10.1038/s41586-018-0375-9

MLA:

Groning, Oliver, et al. "Engineering of robust topological quantum phases in graphene nanoribbons." Nature 560.7717 (2018): 209-213.

BibTeX: Download