Valley-antisymmetric potential in graphene under dynamical deformation

Abstract

When graphene is deformed in a dynamical manner, a time-dependent potential is induced for the electrons. The potential is antisymmetric with respect to valleys, and some straightforward applications are found for Raman spectroscopy. We show that a valley-antisymmetric potential broadens Raman $D$ band but does not affect $2D$ band, which is already observed by recent experiments. The space derivative of the valley antisymmetric potential gives a force field that accelerates intervalley phonons, while it corresponds to the longitudinal component of the previously discussed pseudoelectric field acting on the electrons. Effects of a pseudoelectric field on the electron is quite difficult to observe due to the valley-antisymmetric coupling constant, on the other hand, such obstacle is absent for intervalley phonons with $A_{1g}$ symmetry that constitute the $D$ and $2D$ bands.

11 pages, 3 figures

References in corpus (7)

• Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
• Chiral Gauge Theory for Graphene
• Gauge field for edge state in graphene
• The origin of Raman D Band: Bonding and Antibonding Orbitals in Graphene
• Chirality dependent frequency shift of radial breathing mode in metallic carbon nanotubes
• Kohn Anomaly in Raman Spectroscopy of Single Wall Carbon Nanotubes
• Decay and Frequency Shift of Inter and Intravalley Phonons in Graphene -Dirac Cone Migration-