Spectroscopy of few-electron collective excitations in charge-tunable artificial atoms.
We report the investigation of electronic excitations in InGaAs self-assembled quantum dots using resonant inelastic light scattering. The dots can be charged via a gate by N=1, em leader,6 electrons. We observe excitations, which are identified as transitions of electrons, predominantly from the s to the p shell (s-p transitions) of the quasiatoms. We find that the s-p transition energy decreases and the observed band broadens, when the p shell is filled with 1 to 4 electrons. By a theoretical model, which takes into account the full Coulomb interaction in the few-electron artificial atom, we can confirm the experimental results to be an effect of the Coulomb interaction in the quantum dot.
Brocke
T
T
Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstrasse 11, D-20355 Hamburg, Germany.
Bootsmann
M-T
MT
Tews
M
M
Wunsch
B
B
Pfannkuche
D
D
Heyn
Ch
Ch
Hansen
W
W
Heitmann
D
D
Schüller
C
C