Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 31: Poster II
HL 31.60: Poster
Dienstag, 26. Februar 2008, 16:30–19:00, Poster D
Magneto-Transport in Two-Dimensional Electron Systems beneath Ferromagnetic Nanostructures — •Ralf Dinter1, Holger Stillrich1, Christian Heyn1, Andreas Frömsdorf2, Hans Peter Oepen1, and Wolfgang Hansen1 — 1Institut für Angewandte Physik, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg — 2Institut für Physikalische Chemie, Universität Hamburg, Bundesstr. 45, 20146 Hamburg
We study the magneto-transport of two-dimensional electron systems (2DEG's), which are subjected to laterally modulated magnetic fields. Our goal is to investigate the energy splitting of the Landau levels due to field modulations with periods less than 100 nm. Shallow GaAs/AlGaAs High Electron Mobility Transistors are grown with MBE, where the 2DEG's are located down to less than 20 nm beneath the sample surface. In order to achieve a modulated magnetic potential, a nano-structured Co/Pt multilayer is prepared directly on the samples. Hereby, a monolayer of micelles, consisting of diblock-copolymers, is used as a template. The micelles arrange in a hexagonal lattice with short-range order. The magnetic properties of the ferromagnetic material are studied with the magneto-optical Kerr effect. The magneto-transport is investigated in Hall bar geometry at temperatures between 4.2 K and 20 mK. We present magneto-transport measurements on Hall bars with a modulated magnetic potential.