Hydrogen-designed spin-states of 2D silicon carbide and graphene nanostructures

Identifying and manipulating spin in two-dimensional materials is of great interest in advancing quantum information and sensing technologies, as well as in the development of spintronic devices. Here, we investigate the influence of hydrogen adsorption on the electronic and magnetic properties of graphene-like triangulenes. We have constructed triangulenes from SiC monolayers, which have been successfully synthesized very recently, extending our investigation to include graphene triangulenes. This advancement in the synthesis of SiC monolayers allows us to investigate deeper into the unique properties of SiC-based triangulenes and compare them with their graphene counterparts. The addition of hydrogen has been found to induce a magnetic moment in the SiC monolayer, with a more localized spin density when H is adsorbed in the C sites while spreading through the lattice when adsorbed on the Si sites. In triangular flakes, the ground spin state changes with the adsorption site: decreasing multiplicity on edge-defined sublattices and increasing it on the opposite sublattice. These findings suggest hydrogen adsorption as a tool for tuning spin-state properties in SiC and graphene nanostructures, with potential applications in spintronics and spin quantum dot devices.