Regensburg 2013 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 29: Poster Session: Spintronics; Spin-controled transport; Topological insulators; Interfaces / Surfaces; Magnetic semiconductors

HL 29.26: Poster

Montag, 11. März 2013, 16:00–20:00, Poster A

Anisotropic Magnetotransport in Mn doped, p-type InAs quantum wires — •Sabine Weishäupl¹, Ursula Wurstbauer², Werner Wegscheider³, and Dieter Weiss¹ — ¹Institut für Experimentelle und Angewandte Physik, Universität Regensburg, D-93040 Regensburg — ²Department of Physics, Columbia University, New York, USA — ³Solid State Physics Laboratory, ETH Zurich, Zurich, Switzerland

The ratio of Rashba and Dresselhaus spin-orbit interaction strengths, α and β, can be deduced by measuring the conductance of narrow wires, where the weak antilocalization correction to the conductance is switched off. The in-plane magnetic field direction where the conductance displays a minimum is related directly to the ratio α/β [1].

Motivated by this proposal we have measured the conductance of quantum wires (widths w=150 nm, w=200 nm) in Mn doped, p-type InAs quantum wells as a function of magnetic field, topgate voltage and manganese concentration.

In the out-of-plane configuration, a strong localization in the low field regime is present. At higher fields the localization is lifted and Shubnikov-de-Haas oscillations start to appear. In the in-plane magnetic field, the wires feature an anisotropy which can be tuned by gate voltage, magnetic field strength and temperature.

We compare these samples with similar ones that have lower manganese concentration. With these, weak antilocalization is observed.

[1] M. Scheid et al., Phys. Rev. Lett. 101, 266401 (2008)