Internal transitions of negatively charged magnetoexcitons and many body effects in a two-dimensional electron gas.
Internal transitions of quasi-two-dimensional, negatively charged magnetoexcitons ( X-) and their evolution with excess electron density have been studied in GaAs/AlGaAs quantum wells. In the dilute electron limit, due to magnetic translational invariance, the optically detected resonance spectra are dominated by bound-to-continuum bands in contrast to the negatively charged donor system D-, which exhibits strictly bound-to-bound transitions. With increasing excess electron density Landau-level filling factors nu<2 the X--like transitions are blueshifted; they are absent for nu>2. The blueshifted transitions are explained in terms of a new type of collective excitation---magnetoplasmons bound to a mobile valence band hole.
Nickel
H A
HA
Department of Physics and Center for Advanced Photonic and Electronic Materials, SUNY Buffalo, Buffalo, New York 14260, USA.
Yeo
T M
TM
Dzyubenko
A B
AB
McCombe
B D
BD
Petrou
A
A
Sivachenko
A Yu
AY
Schaff
W
W
Umansky
V
V