Spatially resolved magneto-optics on confined systems

We report about spatially resolved magneto-optical experiments on two diffe rent confined semiconductor systems. Using near-held spectroscopy through A FM-written shadow masks we have investigated the optical properties of sing le self-assembled InGaAs quantum dots as a function of excitation power and magnetic field. This allows us to identify and fully resolve diamagnetic/o rbital effects and the Zeeman splitting in the ground state and excited sta te of a given quantum dot. Further we report on the transport properties of minority holes ina high mobility two-dimensional electron gas at finite el ectric fields and high magnetic fields. Making use of spatially resolved op tical excitation and detection we study the propagation of optically excite d minority holes within the sea of a drifting two-dimensional electron gas. At high magnetic fields we observe an E x B drift of holes which is domina ted by the Hall-field of the electron gas. At the edge of the Hall-bar, we observe edge state transport of holes via skipping orbits opposite to the d irection of the initial Ex B drift. (C) 1998 Elsevier Science B.V. All righ ts reserved.