Dresden 2009 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 34: Spin controlled transport II
HL 34.3: Vortrag
Mittwoch, 25. März 2009, 14:30–14:45, BEY 118
Cascaded Y-shaped InAs Spin Filters — •Jan Jacob1, Guido Meier1, Marc-Antonio Bisotti1, Sebastian Peters1, Toru Matsuyama1, Ulrich Merkt1, Aron Cummings2, Richard Akis2, and David Ferry2 — 1Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Germany — 2Center for Solid State Electronics Research, Department of Electrical Engineering, Arizona State University, Tempe, Arizona 85287-5706
Several all-semiconductor three-terminal devices have been proposed which utilize the intrinsic spin-Hall effect to generate two oppositely spin-polarized currents [1,2]. There are two main obstacles in the experimental realization of these devices: the limitation of electronic transport to only the lowest subband, and the detection of the spin polarization. We present numerical simulations and experimental results of a two-stage cascade of Y-shaped spin-filters based on a two-dimensional electron gas in an InAs heterostructure [3]. The two-stage design allows an all-electrical detection of the spin polarization by using the first filter as a polarizer and the second as an analyzer. The regime of transport in the lowest subband is reached by constricting each part of the device with a quantum-point contact. Experiments and simulations show a high degree of spin polarization for the spin-filter cascade. The influence of magnetic fields is also studied. [1] A. Kiselev and K. Kim, J. Appl. Phys. 94, 4001 (2000) [2] J.I. Ohe et al., Phys. Rev. B 72, 041308(R) (2005) [3] A. Cummings et al., J. App. Phys. 104, 066106 (2008)