Transversal light forces in semiconductors

Abstract

The transversal light force is a well established effect in atomic and molecularsystems that are exposed to spatially inhomogeneous light fields. In this paper itis shown theoretically that in an excited semiconductor, containing anelectron–hole plasma or excitons, a similar light force exists, if the semiconductoris exposed to an ultrashort spatially inhomogeneous light field. The analysis isbased on the equations of motion for the Wigner distribution functions ofcharge carrier populations and interband polarizations. The results showthat, while the light force on the electron–hole plasma or the excitonsdoes exist, its effects on the kinetic behaviour of the electron–hole plasmaor the excitons are different compared to the situation in an atomic ormolecular system. A detailed analysis presented here traces this differenceback to the principal differences between atoms and molecules on theone hand and electron–hole plasmas or excitons on the other hand.