The Possibility of a Solitary Electromagnetic Wave Propagating in Arbitrary Directions in the Plane of a Two-Dimensional Graphene-Based Superlattice

The possibility of a plane solitary electromagnetic wave propagating in the plane of a square two-dimensional graphene-based superlattice at different angles to its axes is investigated. A nonlinear equation describing the vector potential of a solitary electromagnetic wave is obtained for a case of weak nonadditivity of the energy spectrum of carriers in a collisionless approximation. It is shown that plane solitary waves can propagate either along the superlattice axes or at an angle of 45° to them.