Orbital momentum excitation by interband optical transitions in a 2D system illuminated by twisted light

Illumination of a two-dimensional system by a twisted light beam is considered in order to find specific effects caused by twisting. Direct interband transitions between the valence and conduction bands are supposed. The generation rates of the electron orbital momentum is found. A kinetic equation for an orbital momentum distribution function is formulated and solved. The mean electron orbital momentum is found.