Superexchange Mechanism in Coupled Triangulenes Forming Spin-1 Chains
Abstract
We show that the origin of the antiferromagnetic coupling in spin-1 triangulene chains, which were recently synthesized and measured by Mishra et al. Nature 598, 287-292 (2021) originates from a superexchange mechanism. This process, mediated by inter-triangulene states, opens the possibility to control parameters in the effective bilinear-biquadratic spin model. We start from the derivation of an effective tight-binding model for triangulene chains using a combination of tight-binding and Hartree-Fock methods fitted to hybrid density functional theory results. Next, correlation effects are investigated within the configuration interaction method. Our low-energy many-body spectrum for and triangulene chains agree well with the bilinear-biquadratic spin-1 chain antiferromagnetic model when indirect coupling processes, and superexchange coupling between triangulene spins are taken into account.
Keywords
Cite
@article{arxiv.2403.07774,
title = {Superexchange Mechanism in Coupled Triangulenes Forming Spin-1 Chains},
author = {Yasser Saleem and Torben Steenbock and Emha Riyadhul Jinan Alhadi and Weronika Pasek and Gabriel Bester and Pawel Potasz},
journal= {arXiv preprint arXiv:2403.07774},
year = {2024}
}