Near-field spectroscopy of single semiconductor nanostructures

Summary form only given.Quasi-one-dimensional semiconductor structures have attracted much interest, both from the viewpoint of fundamental physics and for device applications. Until now, the optical properties and the nonequilibrium carrier dynamics in such quantum wires (QWRs) have mainly been studied with ensembles of nanostructures, making an analysis of the local confinement potentials and of carrier transport in real space difficult. Spatially resolved experiments with single QWRs provide new insight into such phenomena and allow a separation of transport processes from carrier relaxation in the QWR. In this paper, we present a comprehensive study of the optical properties and the spatio-temporal carrier dynamics in single GaAs quantum wires. The experiments are based on near-field optical microscopy with sub-wavelength spatial resolution in combination with time-resolved spectroscopy.