Low temperature near-field luminescence studies of localized and delocalized excitons in quantum wires.
Excitons in a GaAs quantum wire were studied in high-resolution photoluminescence experiments performed at a temperature of about 10 K with a spatial resolution of 160 nm and a spectral resolution of 100 microeV. We report the observation of quasi-one-dimensional excitons which are delocalized over a length of up to several micrometres along the quantum wire. Such excitons give rise to a 10 meV broad luminescence band, representing a superposition of transitions between different delocalized states. In addition, we find a set of sharp luminescence peaks from excitons localized on a sub150 nm length scale. Theoretical calculations of exciton states in a disordered quasi-one-dimensional potential reproduce the experimental results.
Intonti
F
F
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, D-12489 Berlin, Germany. intonti@mbi-berlin.de
Emiliani
V
V
Lienau
C
C
Elsaesser
T
T
Nötzel
R
R
Ploog
K H
KH