Electron spin - the quantized magnetic moment of electrons - can act as an information carrier in a similar way to electron charge. Graphene has high carrier mobility and a long spin diffusion length, and is therefore considered an ideal spintronic material for long-distance transport of spins. However, inducing spins in graphene is challenging. To overcome this limitation, we are developing porphyrin-graphene nanoribbon (Por-GNB) hybrid structures with embedded transition metal atoms that provide localized spins that interact with the delocalized π-electron spins of the nanoribbon. Our goals are the surface-assisted synthesis of such Por-GNB hybrids with low defect density and the characterization of spin coupling in these systems using scanning probe techniques.

This project will develop accessible routes for the synthesis of Por-GNB hybrid materials and characterize spin coupling and spin transport in these novel systems. To achieve this, we will (i) establish synthetic routes to atomically precise Por-GNB hybrids by surface-assisted synthesis under ultrahigh vacuum conditions, and (ii) tune the spin states of Por-GNBs by varying the incorporated metal species. In addition, we will (iii) confirm the predicted spin states in Por-GNB hybrid systems and (iv) investigate the mechanism of spin coupling depending on the metal species and the nature of Por-GNB hybrids.

Our work will establish a new approach for the fabrication of novel, atomically precise Por-GNB heterostructures. Spin-exchange coupling in such Por-GNBs is achieved at the nanometer scale, significantly increasing the indirect coupling length. The submicrometer length of the targeted Por-GNBs and their highly tunable spin states should make them ideal candidates for spintronic applications.