Many-Body Effects at the Fermi Edge of Modulation Doped Semiconductors: a Numerical Study

Abstract

Optical properties near the Fermi-edge of one-component Coulomb systems have been studied for more than half a century (for recent reviews see [1,2]). Originally the interest was focussed on x-ray spectra of metals. The development of modern crystal-growth technique allowed to realize similar systems in semiconductor materials. In these doped quantum-wells many-body effects which are responsible for the lineshape of optical spectra can be studied over a large range of densities applying the various tools of ultra-short time spectroscopy. The current interest in these systems results as well from the technological importance of them as from conceptual reasons, concerning basic aspects of quantum mechanics and manybody physics. Especially the study of nonlinear optical properties on an ultrashort timescale provides sensitive information about the relevant scattering processes which determine the dephasing and thus the lineshape of nonlinear spectra.