  The electron-phonon matrix elements relevant to the Raman intensity and Kohn
anomaly of the G band are calculated by taking into account the effect of the
edge of graphene. The analysis of the pseudospin reveals that the longitudinal
optical phonon mode undergoes a strong Kohn anomaly for both the armchair and
zigzag edges, and that only the longitudinal (transverse) optical phonon mode
is a Raman active mode near the armchair (zigzag) edge. The Raman intensity is
enhanced when the polarization of the incident laser light is parallel
(perpendicular) to the armchair (zigzag) edge. This asymmetry between the
armchair and zigzag edges is useful in identifying the orientation of the edge
of graphene.
