2023/12/08 by J. C. G. Henriques, David Jacob, Henriques, J. C. G. +9 · 4 citations
Chemistry · Engineering · Materials Science · #Synthesis and Properties of Aromatic Compounds #Molecular Junctions and Nanostructures #Graphene research and applications
paper · pdf · doi:10.48550/arxiv.2312.04938
The study of open-shell nanographenes has relied on a paradigm where spins are the only low-energy degrees of freedom. Here we show that some nanographenes can host low-energy excitations that include strongly coupled spin and orbital degrees of freedom. The key ingredient is the existence of orbital degeneracy, as a consequence of leaving the benzenoid/half-filling scenario. We analyze the case of nitrogen-doped triangulenes, using both density-functional theory and Hubbard model multiconfigurational and random-phase approximation calculations. We find a rich interplay between orbital and spin degrees of freedom that confirms the need to go beyond the spin-only paradigm, opening a new venue in this field of research.