▎ 摘　　要

We consider a dilute fluorinated graphene nanoribbon as a spin-active element. The fluorine adatoms introduce a local spin-orbit Rashba interaction that induces spin precession for electron passing by. The spin precession involving a single adatom is infinitesimal and accumulation of the spin-precession events with many electron passages under adatoms is necessary to accomplish a spin flip. In order to arrange for this accumulation, a circular n-p junction can be introduced to the ribbon by, e.g., potential of the tip of an atomic force microscope. Alternatively, a fluorinated quantum ring can be attached to the ribbon. We demonstrate that the spin-flip probability can be increased in this manner by as much as three orders of magnitude. The Zeeman interaction introduces spin dependence of the Fermi wave vectors which changes the electron paths within the disordered system depending on the spin orientation. The effect destroys the accumulation of the spin-precession events in the n-p junction. For side-attached quantum rings, however, for which the electron path is determined by the confinement within the channel, the accumulation of the spin precession is robust against the Zeeman spin splitting.