Giant magnetic exchange coupling in rhombus-shaped nanographenes with zigzag periphery
Abstract
Nanographenes with zigzag edges are predicted to manifest non-trivial pi-magnetism resulting from the interplay of hybridization of localized frontier states and Coulomb repulsion between valence electrons. This provides a chemically tunable platform to explore quantum magnetism at the nanoscale and opens avenues toward organic spintronics. The magnetic stability in nanographenes is thus far limited by the weak magnetic exchange coupling which remains below the room temperature thermal energy. Here, we report the synthesis of large rhombus-shaped nanographenes with zigzag periphery on gold and copper surfaces. Single-molecule scanning probe measurements unveil an emergent magnetic spin-singlet ground state with increasing nanographene size. The magnetic exchange coupling in the largest nanographene, determined by inelastic electron tunneling spectroscopy, exceeds 100 meV or 1160 K, which outclasses most inorganic nanomaterials and remarkably survives on a metal electrode.
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Cite
@article{arxiv.2003.03577,
title = {Giant magnetic exchange coupling in rhombus-shaped nanographenes with zigzag periphery},
author = {Shantanu Mishra and Xuelin Yao and Qiang Chen and Kristjan Eimre and Oliver Groening and Ricardo Ortiz and Marco Di Giovannantonio and Juan Carlos Sancho-Garcia and Joaquin Fernandez-Rossier and Carlo A. Pignedoli and Klaus Muellen and Pascal Ruffieux and Akimitsu Narita and Roman Fasel},
journal= {arXiv preprint arXiv:2003.03577},
year = {2021}
}
Comments
4 figures plus supplementary information