%0 Journal Article
%A de Filippis, G.
%A Cataudella, V.
%A Mishchenko, A. S.
%A Perroni, C. A.
%A Devreese, J. T.
%T Validity of the Franck-Condon principle in the optical spectroscopy: optical conductivity of the Fröhlich polaron
%J Physical review letters
%V 96
%@ 0031-9007
%C College Park, Md.
%I APS
%M PreJuSER-57567
%P 136405
%D 2006
%Z Record converted from VDB: 12.11.2012
%X The optical absorption of the Frohlich polaron model is obtained by an approximation-free diagrammatic Monte Carlo method and compared with two new approximate approaches that treat lattice relaxation effects in different ways. We show that: (i) a strong coupling expansion, based on the Franck-Condon principle, well describes the optical conductivity for large coupling strengths (alpha > 10); (ii) a memory function formalism with phonon broadened levels reproduces the optical response for weak coupling strengths (alpha < 6) taking the dynamic lattice relaxation into account. In the coupling regime 6 <alpha < 10, the optical conductivity is a rapidly changing superposition of both Franck-Condon and dynamic contributions.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000236612400045
%$ pmid:16712012
%R 10.1103/PhysRevLett.96.136405
%U https://juser.fz-juelich.de/record/57567