TY  - JOUR
AU  - de Filippis, G.
AU  - Cataudella, V.
AU  - Mishchenko, A. S.
AU  - Perroni, C. A.
AU  - Devreese, J. T.
TI  - Validity of the Franck-Condon principle in the optical spectroscopy: optical conductivity of the Fröhlich polaron
JO  - Physical review letters
VL  - 96
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - PreJuSER-57567
SP  - 136405
PY  - 2006
N1  - Record converted from VDB: 12.11.2012
AB  - 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.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000236612400045
C6  - pmid:16712012
DO  - DOI:10.1103/PhysRevLett.96.136405
UR  - https://juser.fz-juelich.de/record/57567
ER  -