Exciton dephasing in quantum dot molecules.
We have measured the exciton dephasing time in InAs/GaAs quantum dot molecules having different interdot barrier thicknesses in the temperature range from 5 to 60 K, using a highly sensitive four-wave mixing heterodyne technique. At 5 K dephasing times of several hundred picoseconds are found. Moreover, a systematic dependence of the dephasing dynamics on the barrier thickness is observed. These results show how the quantum-mechanical coupling of the electronic wave functions in the molecules affects both the exciton radiative lifetime and the exciton-acoustic phonon interaction.
Borri
P
P
Experimentelle Physik II, Universität Dortmund, Otto-Hahn Strasse 4, D-44227 Dortmund, Germany.
Langbein
W
W
Woggon
U
U
Schwab
M
M
Bayer
M
M
Fafard
S
S
Wasilewski
Z
Z
Hawrylak
P
P