Phonon Quantum Kinetics In Spatially Inhomogeneous Systems

The dynamics of optically generated carriers interacting with longitudinal optical phonons is analyzed on a quantum kinetic level for the case of a spatially inhomogeneous excitation and the presence of a spatially inhomogeneous potential. The density matrix theory is extended to account for spatial inhomogeneities and the various contributions entering the dynamical equations are discussed. The theory is applied to the dynamics of a wave packet optically generated locally in a quantum wire. We study quantum kinetic features in the expansion process, the generation of coherent phonon amplitudes, and the capture into localized states in a quantum dot embedded in the quantum wire.