Berlin 2008 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 31: Poster II

HL 31.11: Poster

Dienstag, 26. Februar 2008, 16:30–19:00, Poster D

Characterization and Weak-Antilocalization measurements of InGaAs/InP quantum wire structures — •Markus Hagedorn, Masashi Akabori, Hilde Hardtdegen, Vitaliy Guzenko, and Thomas Schäpers — Institute of Bio- and Nanosystems (IBN-1) and Centre of Nanoelectronic Systems for Information Technology (CNI), Research Centre Jülich, 52425 Jülich, Germany

We report on the investigation of InGaAs/InP quantum wire structures with respect to a general characterization and spin-related effects such as weak-anti-localization (WAL) by performing magnetoresistance measurements at low temperatures. The thickness of the InGaAs channel layer (Indium content of 77%) is varied systematically in the range of 2 to 10 nm in order to study the influence of the quantum well width on the WAL and therefore on the spin-orbit-coupling. By means of a He3-cryostat, low temperature transport measurements (around 0.6K) were performed using e-beam written array wire structures which allow to study a set of different wire widths in the range of 100 to 1000nm. Additionally each structure has also a Hall bar to provide further analysis of beating pattern nodes and heterostructure properties such as mobility and carrier concentration. Analysis of the WAL on the one hand and the node position shift in the beating pattern observed in the Shubnikov-de Haas oscillations on the other hand, show clearly that the smallest channel layer thickness correspond to a large Rashba spin-orbit coupling.