ELECTRON-LO-PHONON QUANTUM KINETICS IN SEMICONDUCTOR QUANTUM-WELLS

Quantum correlations between electrons and phonons are demonstrated in two-dimensional semiconductors. The resulting phonon oscillation exhi bits characteristic differences with respect to the three-dimensional parent system. We show how these correlations can unambiguously be dis tinguished from nonequilibrium coherent phonons. Furthermore, coherent control allows separation of the phonon oscillation from another osci llation observed here, specific to two-dimensional systems, which is d ue to the interference of two electron-electron scattering channels as sociated with different quantum-well subbands.