Charge-transfer-induced nesting antiferromagnetism in 2D hydrogen-bonded organic frameworks.

Non-relativistic spin-split (NRSS) antiferromagnets (AFMs) have become a research focus in the field of antiferromagnetic spintronics due to their advantages such as avoiding spin dephasing caused by strong spin-orbital coupling and having no stray magnetic fields. Γ-split AFMs are a distinct class of NRSS AFMs, featuring overall spin splitting specifically at the Brillouin zone's Γ point. To date, their realization has been confined to a handful of inorganic materials. Molecular frameworks are a promising platform for achieving multiple exotic properties and tunability due to their diverse ligand types and symmetries. Herein, we propose that Γ-split AFMs can be realized in 2D hydrogen-bonded organic frameworks (HOFs) via nesting honeycomb and Kagome lattices. In these 'nesting AFMs', each sublattice is ferromagnetic with opposite spin polarization, constructed separately using donor and acceptor molecules. Density functional theory calculations confirm that five designed nesting HOFs are nesting AFMs. Importantly, the ferromagnetic ordering of each sublattice originates from charge transfer between hydrogen-bond-connected donors and acceptors. This work provides a practical strategy to design novel low-dimensional molecule-based NRSS AFMs for antiferromagnetic spintronics.