Coherent control of electron-phonon quantum kinetics: exploring the weak and the strong coupling regime

We present an investigation of the very early stage of the dynamics of opti cally excited semiconductors in the Quantum Kinetics regime. We demonstrate that the wave-like nature of electronic elementary excitations can be obse rved during their interaction and, furthermore, that this interaction can b e quantum mechanically controlled by use of phase locked laser pulses. We p resent a simple model that accounts well for the experimental results for t he small and large coupling constants case, and also provides an intuitive understanding of the underlying physics. (C) 2000 Elsevier Science B.V. All rights reserved.