Nature Communications (Oct 2023)

Detecting the spin-polarization of edge states in graphene nanoribbons

  • Jens Brede,
  • Nestor Merino-Díez,
  • Alejandro Berdonces-Layunta,
  • Sofía Sanz,
  • Amelia Domínguez-Celorrio,
  • Jorge Lobo-Checa,
  • Manuel Vilas-Varela,
  • Diego Peña,
  • Thomas Frederiksen,
  • José I. Pascual,
  • Dimas G. de Oteyza,
  • David Serrate

DOI
https://doi.org/10.1038/s41467-023-42436-7
Journal volume & issue
Vol. 14, no. 1
pp. 1 – 8

Abstract

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Abstract Low dimensional carbon-based materials can show intrinsic magnetism associated to p-electrons in open-shell π-conjugated systems. Chemical design provides atomically precise control of the π-electron cloud, which makes them promising for nanoscale magnetic devices. However, direct verification of their spatially resolved spin-moment remains elusive. Here, we report the spin-polarization of chiral graphene nanoribbons (one-dimensional strips of graphene with alternating zig-zag and arm-chair boundaries), obtained by means of spin-polarized scanning tunnelling microscopy. We extract the energy-dependent spin-moment distribution of spatially extended edge states with π-orbital character, thus beyond localized magnetic moments at radical or defective carbon sites. Guided by mean-field Hubbard calculations, we demonstrate that electron correlations are responsible for the spin-splitting of the electronic structure. Our versatile platform utilizes a ferromagnetic substrate that stabilizes the organic magnetic moments against thermal and quantum fluctuations, while being fully compatible with on-surface synthesis of the rapidly growing class of nanographenes.