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The European Physical Journal B
ISSN: 1434-6028 (printed version)
ISSN: 1434-6036 (electronic version)
Abstract Volume 1 Issue 2 (1998) pp 209-213
Self-consistent RPA retarded polaron Green function for quantum kinetics
L. Bányai (1) (a), H. Haug (1), P. Gartner (2)
(1) Institut für Theoretische Physik der Universität, Frankfurt am Main, Germany
(2) Institute of Physics and Technology of Materials, Bucharest
Received: 18 September 1997 / Revised: 24 October 1997 / Accepted: 6 November 1997
Abstract: We compute numerically the time dependent retarded Green function of the polaron within the self-consistent RPA approximation. The results show an approximately Gaussian behaviour at t=0 changing at later times its concavity to an exponential decay, as it has been predicted in the approximate form of an inverse hyperbolic cosine function. The result contrasts with the non-selfconsistent RPA, where the exponential decay is only a transitory behaviour and the asymptotics is rather oscillatory. Our conclusions are significant in the context of the quantum kinetics with LO-phonons, where the transition from an intitially coherent scattering kinetics to a Markov kinetics with energy conservation is controlled by the time behaviour of the retarded Green function.
PACS. 78Optical properties, condensed-matter spectroscopy and other interactions of radiation and particles with condensed matter - 71.38.+iPolarons and electron-phonon interactions
(a) e-mail: bla@mandala.th.physik.uni-frankfurt.de
Online publication: February 17, 1998
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