Comparison of Classical Molecular Dynamics and Ab Initio Modeling of Discrete Breathers in Graphene

A density functional theory based method was used to model dynamics of high frequency delocalized normal mode and discrete breathers in graphene at T = 0 K. For the normal mode the comparison of results was made with modeling by means of classical molecular dynamics. Discrete breathers have been found only in presence of uniaxial strain applied in “zigzag” direction. The oscillations of breather core atoms appeared to be polarized along “arm-chair” direction. In the case of “arm-chair” uniaxial strain there were no breathers found. The frequency on the amplitude dependency of DBs in graphene corresponds to the soft nonlinearity type that is due to the soft nonlinearity type of the high frequency normal mode on which breather is constructed.