Zone folding effect in Raman G-band intensity of twisted bilayer graphene

• Main Authors: Sato, Kentaro (Author), Saito, Riichiro (Author), Cong, Chunxiao (Author), Yu, Ting (Author), Dresselhaus, Mildred (Contributor)
• Other Authors: Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2013-01-07T18:23:29Z.
• Subjects: Article
• Online Access: Get fulltext

The G-band Raman intensity is calculated for twisted bilayer graphene as a function of laser excitation energy based on the extended tight binding method. Here we explicitly consider the electron-photon and electron-phonon matrix elements of twisted bilayer graphene to calculate the resonance Raman intensity. The G-band Raman intensity is sensitive to the laser excitation energy and the twisting angle between the layers as a result of folding the electronic energy band structure. The Van Hove energy singularity, which is an electron transition energy between the conduction and valence bands, depends on n−m of the twisting vector (n,m). The relative intensity of the G band as a function of twisting vectors is presented, which should be useful for the experimental identification of the twisting angle.
National Science Foundation (U.S.) (Grant DMR-10- 1004147)