Dresden 2003 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 32: Spinabh
ängiger Transport II
HL 32.7: Vortrag
Mittwoch, 26. März 2003, 16:00–16:15, POT/81
ZnMnSe-Spinaligner on GaAs/AlGaAs-Heterostructures — •T. Leeb1, M. Döppe1, D. Weiss1, W. Wegscheider1, D. Schuh2, M. Bichler2 und G. Abstreiter2 — 1Institut für Experimentalphysik, Universität Regensburg, D-93040 Regensburg, Germany — 2Walter Schottky Institut, TU München, D-85748 Garching, Germany
Several groups have verified the function of Mn-doped II-VI-semiconductors as a spinaligner in semiconductor optical devices [1], [2]. Spin injection into a two dimensional electron system (2DES) is still a challenge which has not yet been mastered. We have grown n-doped Zn1−xMnxSe contact-layers on an inverted GaAs/AlGaAs-2DES-structure specially designed to reduce conduction band barriers that could increase spin scattering. GaAs surface preparation and ZnMnSe growth start are crucial for achieving this electronic structure at the ZnMnSe/GaAs-interface. Photoluminescense measurements show a strong conduction band splitting of the Zn1−xMnxSe at small external magnetic fields for different Mn content x. This leads to a vanishing transmission coefficient for minority spin electrons. Magnetotransport measurements have been successfully performed using a van-der-Pauw contact geometry. However, theoretical considerations suggest that to experimentally verify spin injection in electronic transport the sample has to be structured on micrometer lengthscales to overcome spin equilibration between quantum hall edge channels. This work is supported by DFG via SFB 348 and by BMBF 13N8282.
[1] Nature 402, 787 (1999)
[2] APL 74, 1251 (1999)