Berlin 2008 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 51: Poster IV

HL 51.22: Poster

Donnerstag, 28. Februar 2008, 16:30–19:00, Poster D

Micromechanical cantilever magnetometer with in situ tunable sensitivity on a rotational stage — •Wolfgang Krenner, Xuting Huang, Tjark Windisch, Marc A. Wilde, and Dirk Grundler — Physik Department E10, Technische Universität München, James-Franck-Str. 1, D-85748 München

We report on a micromechanical cantilever magnetometer (MCM) mounted on a rotational sample stage incorporating a piezoceramics nanopositioning system. The MCM is read out by measuring the capacitance between the metalized backside and a fixed counter electrode. By tuning the piezoceramics we optimize the MCM’s sensitivity at 300 mK in situ and in a magnetic field B of up to 16 T. With this setup we investigate the de Haas-van Alphen (dHvA) effect of 2D electron systems in III-V semiconductor heterostructures. At low temperature T the magnetization M=−∂ U/∂ B provides direct information on U, the ground state energy. We discuss InAs-based and Mn-doped heterostructures where spin-orbit interaction is expected to induce beating patterns in the dHvA oscillations. The ability to rotate the sample allows us to adjust perpendicular and in-plane magnetic field components, which affect the Landau and Zeeman splitting differently. By this means we intend to investigate the spin splitting mechanisms in detail. First results will be presented.
We thank O. Roesler for technical assistance, A. Fontcuberta i Morral, Ch. Heyn, T. Schaepers, and W. Wegscheider for providing samples and the DFG for financial support via the "Nanosystems Initiative Munich (NIM)" and SPP 1285 Halbleiter Spinelektronik.