Quasiparticle band gaps of graphene nanowiggles and their magnetism on Au(111)

Periodic repetitions of nonaligned and finite-sized graphene nanoribbon domains, known as graphene nanowiggles, can be synthesized using a surface-assisted bottom-up approach. They have been predicted to possess unusual properties such as tunable band gaps and versatile magnetic behaviors. Here, a first-principles many-body Green's function approach within the GW approximation is used to accurately compute their band gaps, which are in the range 0.00-3.65 eV depending on geometry and magnetism. We also perform spin-polarized density functional theory calculations to demonstrate that the previously predicted complex spin states for free-standing nanowiggles are not significantly altered by the presence of the gold substrate on which they are synthesized.