Interplay between Coulomb interaction and quantum interference in three-level resonant asymmetric double quantum wells

A many-body density-matrix theory is derived by including quasiparticle renormalization of kinetic energy and dipole coupling to an external electromagnetic field, as well as the screening and quantum-interference effects. This theory is applied to a three-level resonant asymmetric double-quantum-well system in which the ground subband is coupled to the upper tunneling-split doublet by a strong external electromagnetic field. By using this theory, the quasiparticle energy-level separations and off-diagonal radiative-decay coupling rates, absorption coefficient, refractive-index function, and scaled subband electron density are calculated as functions of incident photon energy. The effects of quasiparticle renormalization on the quantum interference between a pair of optically induced polarizations are analyzed. The quantum interference is shown to be robust against the Coulomb-interaction effect in the mean-field approximation. The roles played by the dephasing rate and electron density are explained.