Correlated electrons in optically tunable quantum dots: building an electron dimer molecule.
We observe the low-lying excitations of a molecular dimer formed by two electrons in a GaAs semiconductor quantum dot in which the number of confined electrons is tuned by optical illumination. By employing inelastic light scattering we identify the intershell excitations in the one-electron regime and the distinct spin and charge modes in the interacting few-body configuration. In the case of two electrons, a comparison with configuration-interaction calculations allows us to link the observed excitations with the breathing mode of the molecular dimer and to determine the singlet-triplet energy splitting.
Singha
Achintya
A
NEST, Istituto di Nanoscienze-CNR and Scuola Normale Superiore, Pisa 56127, Italy.
Pellegrini
Vittorio
V
Pinczuk
Aron
A
Pfeiffer
Loren N
LN
West
Ken W
KW
Rontani
Massimo
M