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HL: Halbleiterphysik

HL 49: Poster II

HL 49.77: Poster

Donnerstag, 27. März 2003, 16:30–19:00, HSZ/P2

Cantilever magnetometry of quantum wires and quantum dots — •J.I. Springborn, M.A. Wilde, M.P. Schwarz, D. Grundler, Ch. Heyn, and D. Heitmann — Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg

The magnetization is a fundamental thermodynamic quantity and monitors the change of the ground state energy of an electron system in a magnetic field. In nanostructured systems it therefore reflects the effect of the confinement and the electron-electron interaction. We have developed highly sensitive micromechanical cantilever magnetometers which incorporate the nanostructured electron systems [1]. In particular these are quantum wires and quantum dots which are prepared from modulation-doped AlGaAs/GaAs-heterostructures by means of laser-interference lithography and reactive-ion etching. Magnetization data are obtained at low temperatures down to 300mK and in magnetic fields up to 16 Tesla. We observe de Haas-van Alphen like oscillations of the magntetic moment. The shape and the amplitude suggest a strong influence of the electron-electron interaction. Simulations confirm our interpretation.

Financial support by the Deutsche Forschungsgemeinschaft via SFB 508 and “Gr1640/1-2” in the “Schwerpunktprogramm Quanten-Hall Systeme” is gratefully acknowledged.

[1] M.P. Schwarz, D. Grundler, M. Wilde, Ch. Heyn, and D. Heitmann, J. Appl. Phys. 91, 6875 (2002).