Regensburg 2004 – wissenschaftliches Programm

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.66: Poster

Montag, 8. März 2004, 16:30–19:00, Poster A

Monolithic cantilever magnetometers with integrated quantum wires — •J.I. Springborn, M.A. Wilde, O. Rösler, M.P. Schwarz, Ch. Heyn, D. Heitmann, and D. Grundler — Institut für Angewandte Physik, Universität Hamburg, Jungiusstraße 11, 20355 Hamburg

The magnetization M is a fundamental thermodynamic quantity and monitors the change of the ground state energy U of an electron system in a magnetic field B. We are in particular interested in the ground state energy of confined and interacting electrons. For this, we have developed highly sensitive micromechanical cantilever magnetometers which incorporate the nanostructured electron systems [1]. Here, we discuss quantum wires which are prepared of modulation-doped AlGaAs/GaAs-heterostructures by means of laser-interference lithography and reactive-ion etching. The smallest quantum-wire width is 200 nm where only a few one-dimensional subbands are occupied. Magnetization data are obtained at low temperatures down to 270 mK and in fields B up to 16 T. We find de Haas-van Alphen like oscillations of M. They directly reflect the effect on U of both, the confinement potential and the electron-electron interaction in a one-dimensional electron system.

We are grateful for being supported by the Deutsche Forschungsgemeinschaft via “SFB 508” and “Gr1640/1-2” in the “Schwerpunktprogramm Quanten-Hall Systeme”.

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