Influence of Many-Body Interactions on the Excitonic Optical Stark Effect

Abstract

Band-edge absorption spectra for a probe beam under the action of a nonresonant pump beam are calculated and analyzed within the Hartree-Fock theory. As a result of many-body interactions, one obtains an exciton optical Stark shift with a constant (2D) or slightly increasing (3D) exciton oscillator strength in agreement with several recent experiments and in striking contrast to corresponding atomic observations. Apparently, the deviating results of earlier semiconductor experiments were partly caused by dynamical effects and partly by the presence of real excitations.