Regensburg 2002 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 11: Poster 1

HL 11.42: Poster

Montag, 11. März 2002, 17:00–19:30, Poster A

Micromechanical cantilever magnetometry on patterned electron systems — •M.A. Wilde, M.P. Schwarz, D. Grundler, Ch. Heyn, and D. Heitmann — Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg

We have developed highly sensitive micromechanical cantilever magnetometers (MCMs) which incorporate micro- and nanostructured electron systems [1]. These are formed in GaAs/AlGaAs heterostructures which are integrated into the sensors by molecular beam epitaxy. The high sensitivity of the MCMs allows us to detect the small signals arising from the orbital magnetism of the conduction band electrons. In large-area two-dimensional electron systems (2DES) we observe sawtooth-like de Haas-van Alphen oscillations. In order to investigate the effect of a lateral confining potential the 2DES are patterned into periodic arrays, using contact- and laser-interference lithography on the cantilever beam. Our experimental results on quantum dots containing only a few 100 electrons suggest a strong influence of the lateral confining potential and of the electron-electron interaction on the magnetization.

Financial support by the Deutsche Forschungsgemeinschaft via SFB 508 and “Gr1640/1-1” in the “Schwerpunktprogramm Quanten-Hall Systeme” is gratefully acknowledged.

[1] M.P. Schwarz, D. Grundler, I. Meinel, C. Heyn and D. Heitmann, Appl. Phys. Lett. 76, 3564 (2000).