InGaAs/GaAs/alkanethiolate radial superlattices: Experimental

A radial InGaAs/GaAs/1-hexadecanethiol superlattice is fabricated by the roll-up of a strained InGaAs/GaAs bilayer passivated with a molecular self-assembled monolayer. Our technique allows the formation of multi-period inorganic/organic hybrid heterostructures. This paper contains the detailed experimental description of how to fabricate these structures.Comment: 2 pages, no figures, Version 2; minor changes (fixed typos and update references

Interaction Effects in Conductivity of Si Inversion Layers at Intermediate Temperatures

We compare the temperature dependence of resistivity \rho(T) of Si MOSFETs with the recent theory by Zala et al. This comparison does not involve any fitting parameters: the effective mass m* and g*-factor for mobile electrons have been found independently. An anomalous increase of \rho with temperature, which has been considered a signature of the "metallic" state, can be described quantitatively by the interaction effects in the ballistic regime. The in-plane magnetoresistance \rho(B) is qualitatively consistent with the theory; however, the lack of quantitative agreement indicates that the magnetoresistance is more susceptible to the sample-specific effects than \rho(T).Comment: 4 pages, 5 figures. References update

Die Shoemaker und Strangways-Krater: Zwei Impaktstrukturen in Australien in der GIS-gestützten Analyse von Fernerkundungs- und Geländedaten

Die Berücksichtigung von Fernerkundungsdaten in geologischen Informationssystemen (GIS) bietet für die Erkundung von terrestrischen Impaktstrukturen neuartige Möglichkeiten. Am Beispiel der komplexen proterozoischen Impaktkrater Shoemaker und Strangways wird gezeigt, dass die Einbindung multispektraler Landsat TM-Daten, Radardaten (ERS-2), geophysikalischer Daten (Aeromagnetik, Aeroradiometrie), Geländebefunden und bereits vorhandener geologischer Karteninformation in ein GIS raumbezogene Abfragen gestattet und z.T. Wissenslücken schließen kann. So lassen sich ursprüngliche Kraterdurchmesser und Erosionsniveaus für beide Strukturen besser abschätzen

Three-Dimensionally Confined Optical Modes in Quantum Well Microtube Ring Resonators

We report on microtube ring resonators with quantum wells embedded as an optically active material. Optical modes are observed over a broad energy range. Their properties strongly depend on the exact geometry of the microtube along its axis. In particular we observe (i) preferential emission of light on the inside edge of the microtube and (ii) confinement of light also in direction of the tube axis by an axially varying geometry which is explained in an expanded waveguide model.Comment: 5 pages, 4 figure