Uncovering the Triplet Ground State of Triangular Graphene Nanoflakes Engineered with Atomic Precision on a Metal Surface

Description

OPEN DATA related to the research publication: J. Li, S. Sanz, J. Castro-Esteban, M. Vilas-Varela, N. Friedrich, T. Frederiksen, D. Peña, and J. I. Pascual, Uncovering the triplet ground state of triangular graphene nanoflakes engineered with atomic precision on a metal surface, Phys. Rev. Lett. 124, 177201 (2020) [arXiv:1912.08298] Abstract: Graphene can develop large magnetic moments in custom-crafted open-shell nanostructures such as triangulene, a triangular piece of graphene with zigzag edges. Current methods of engineering graphene nanosystems on surfaces succeeded in producing atomically precise open-shell structures, but demonstration of their net spin remains elusive to date. Here, we fabricate triangulenelike graphene systems and demonstrate that they possess a spin S=1 ground state. Scanning tunneling spectroscopy identifies the fingerprint of an underscreened S=1 Kondo state on these flakes at low temperatures, signaling the dominant ferromagnetic interactions between two spins. Combined with simulations based on the meanfield Hubbard model, we show that this S=1 π paramagnetism is robust and can be turned into an S=1/2 state by additional H atoms attached to the radical sites. Our results demonstrate that π paramagnetism of high-spin graphene flakes can survive on surfaces, opening the door to study the quantum behavior of interacting π spins in graphene systems.

Resources

Name Format Description Link
0 http://data.europa.eu/88u/dataset/oai-zenodo-org-4243077
0 http://data.europa.eu/88u/dataset/oai-zenodo-org-4243077

Tags

  • dft
  • density-functional-theory
  • magnetism
  • siesta
  • scanning-tunneling-microscopy
  • triplet-state
  • on-surface-synthesis
  • kondo-effect
  • sisl
  • nanoflake
  • triangulene
  • spring
  • spin-polarization
  • meanfield-hubbard-model
  • scanning-tunneling-spectroscopy
  • graphene

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