Electronic and Magnetic Structure of Metal-Organic Lattices on Substrates*

Two-dimensional (2D) metal-organic frameworks (MOFs) have received substantial interest as potential new electronic materials, although their interactions with substrates have received little theoretical attention to date. We employ tools such as density functional theory (DFT), tight-binding, and mean-field Hubbard to investigate these systems. In particular, we focus on 2D MOFs with kagome geometry, where native electronic flat bands can give rise to strong electron-electron interactions. Owing to the latter, we find that a metal-organic dicyanoanthracene kagome lattice can exhibit frustrated antiferromagnetism for specific band filling factors. Different metallic substrates can support or suppress magnetism, as shown by both DFT and experimental measurements. We also investigate the effects of a decoupling atomically thin insulator (hexagonal boron nitride), and the consequences of MOF-surface interactions on previously predicted topological edge states.