Phonon-induced exciton dephasing in quantum dot molecules.
A new microscopic approach to the optical transitions in quantum dots and quantum dot molecules, which accounts for both diagonal and nondiagonal exciton-phonon interaction, is developed. The cumulant expansion of the linear polarization is generalized to a multilevel system and is applied to calculation of the full time dependence of the polarization and the absorption spectrum. In particular, the broadening of zero-phonon lines is evaluated directly and discussed in terms of real and virtual phonon-assisted transitions. The influence of Coulomb interaction, tunneling, and structural asymmetry on the exciton dephasing in quantum dot molecules is analyzed.
Muljarov
E A
EA
Institut für Physik der Humboldt-Universität zu Berlin, Newtonstrasse 15, D-12489 Berlin, Germany. muljarov@gpi.ru
Takagahara
T
T
Zimmermann
R
R