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Figure 4: Multiple-resonance processes for the D and bands. On the left, the first Brillouin zone showing two electronic Dirac cones for the electron dispersion in the nonequivalent K and K′ points. The green wavy arrow indicates the incoming photon. The electronic transition induced by the incoming light is indicated by the green upwards arrow. The phonon-induced transitions are indicated by black arrows: the G band phonon (vertical downwards), the D and band phonons (diagonal black solid arrows) and a nonresonant process (diagonal black dashed arrow). On the top right, the graphene phonon dispersion with the D and band energy and momentum indicated by the vertical arrows. On the bottom right, the optical phonon eigenvectors for the high-symmetry and K points.