Quasiparticle properties of doped quantum-well systems

A two-pole model for the inverse dielectric matrix for a doped quantum-well system is developed, including both intraband and interband excitations. Using this model response function, the quasiparticle properties in GaAs quantum wells are investigated within the GW approximation for the electron self-energy. It is found that, for wide wells, intersubband scattering terms contribute significantly to the subband-gap renormalization, effective-mass changes, and quasiparticle lifetimes. It is found that intersubband electron-electron scattering rates may be similar to those for LO-phonon emission, while intrasubband rates can be an order of magnitude higher.