Investigation of phonon dispersion and strain effects in graphene

In this article the phonon dispersion and strain effects on the band structure of graphene are investigated using density functional theory. The calculated phonon dispersions of graphene show that the LA and TA branches are linear around the -point while the ZA mode shows quadratic energy dispersion. Also, the LO and TO modes at Γ, the LO and LAmodes at K, and the ZA and ZO modes at K are doubly degenerate. The electronic band structure of strained graphene maintains the feature of the bands without applying the strain including a pair of two linear dispersive bands crossing at the Fermi level, the Dirac point position and a small asymmetry in the two linear dispersive bands.

Keywords:

Phonon dispersion , Electronic band structure , Graphene , Density functional theory