Temporally and Spatially Resolved Electron–Phonon Quantum Kinetics

Titelangaben

Herbst, M. ; Axt, Vollrath Martin ; Kuhn, Tilmann:
Temporally and Spatially Resolved Electron–Phonon Quantum Kinetics.
In: Physica Status Solidi B. Bd. 221 (2000) Heft 1 . - S. 419-424.
ISSN 1521-3951
DOI: https://doi.org/10.1002/1521-3951(200009)221:1<419::AID-PSSB419>3.0.CO;2-I

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Abstract

A quantum kinetic theory that is able to resolve interaction processes between carriers and phonons in time and in space is presented. The dynamics of spatially localized wave-packets is analyzed accounting for coherent as well as incoherent phonons. It is found that, as a consequence of the energy–time uncertainty, a fast initial carrier transport takes place leading to occupations of space regions which are out of reach at early times within a semiclassical description on the level of the Boltzmann equation. The charge separation that accompanies the transport of electrons is a source of coherent phonons. The corresponding polarizations of the ion-lattice show oscillations that form a spatially expanding wavefront. Adding incoherent phonons leads to a damping of these waves due to phonon-assisted carrier redistributions.