T-matrix approach for the optical spectra of semiconductor heterostructures

Summary form only given. Coulomb correlations are crucial for the realistic computation of semiconductor optical spectra. In low-dimensional systems, band structure and quantum confinement effects play also a major role and have to be integrated in the theory. In our approach, the excited semiconductor is described by nonequilibrium Green's functions for the interacting quasi-particles: carriers, photons, and plasmons, whose time evolution is governed by Dyson equations. Coupled band structure and quantum confinement effects are included in the carrier propagators, and in the transition matrix elements, which give rise to optical selection rules. We show absorption spectra of a 50-A GaAs-AlGaAs QW, as well as corresponding luminescence spectra.