Figure 5: Intensity resonance of the C and G modes.
From: Resonant Raman spectroscopy of twisted multilayer graphene
(a) Band structure of (1,9) t(1+1)LG. The optically allowed transitions are marked by dashed arrows. The transitions with energy ~1.15 eV between parallel bands along K-M are forbidden, as indicated by solid arrows with crosses. (b) Squared optical matrix elements of the corresponding band pairs in a. (c) Band structure of (1,9) t(1+3)LG. Some typical transitions are indicated by vertical dashed lines. (d) A(G) of t(1+1)LG, (e) A(G−) and A(G+) of t(1+3)LG, and (f) A(C31) and A(C32) as a function of laser excitation energy. The filled circles and open diamonds are the experimental data, while the solid lines show the simulations. The grey dash–dotted lines in e and f are the electronic joint density of states (JDOSs) of all the optically allowed transitions (JDOSOAT) in t(1+3)LG along Γ-K-M-Γ. The VHSs of JDOSOAT are indicated with arrows.
