  Finite size armchair graphene nanoribbons (GNR) of different families are
theoretically studied using the Hubbard model in both mean-field and GW
approximations, including spin correlation effects. It is shown that
correlation primarily affect the properties of topological end states of the
nanoribbons. A representative structure of each of the three GNR families is
considered but the 7-atom width nanoribbon is studied in detail and compared to
experimental results, showing a clear improvement when correlations are
included. Using on numerically computed local density of states, spin-polarized
measurements in scanning tunneling microscopy are also suggested to help
distinguish and highlight correlation effects.
