Uncovering the Triplet Ground State of Triangular Graphene Nanoflakes Engineered with Atomic Precision on a Metal Surface
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Li, Jingcheng
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Sanz, Sofia
2
- Castro-Esteban, Jesus 3
- Vilas-Varela, Manuel 3
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Friedrich, Niklas
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Frederiksen, Thomas
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- Peña, Diego 3
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Pascual, Jose Ignacio
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1
Centro de Investigación Cooperativa en Nanociencias
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Centro de Investigación Cooperativa en Nanociencias
San Sebastián, España
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2
Donostia International Physics Center
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- 3 CiQUS & Universidade de Santiago de Compostela
- 4 DIPC & Ikerbasque
- 5 CIC nanoGUNE & Ikerbasque
Editor: Zenodo
Año de publicación: 2020
Tipo: Dataset
Resumen
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, <em>Uncovering the triplet ground state of triangular graphene nanoflakes engineered with atomic precision on a metal surface</em>, Phys. Rev. Lett. <strong>124</strong>, 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.