Enhancement of the Raman scattering intensity in folded bilayer graphene

We found Raman scattering enhancement of the Raman G band in folded bilayer graphene. Its Raman intensity is more than 40 times greater than that of AB stacked Bernal bilayer graphene. The enhancement is interpreted as being caused by resonant Raman scattering via the π 2 * and the π 1 * states in the modified electronic band structure of the folded bilayer graphene. This enhancement of the Raman G band is a critical indicator of the strength of the coupling between the upper and the lower graphene sheets.