Regensburg 2010 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 33: Poster I: Transport, including Magnetic-Field Effects
HL 33.13: Poster
Dienstag, 23. März 2010, 18:30–20:30, Poster D1
Towards a local spin-valve signal in all-semiconductor lateral spin injection devices. — •Christian Wolf, Andreas Einwanger, Mariusz Ciorga, Martin Utz, Dieter Schuh, and Dieter Weiss — Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg
In our recent experiments [1] we demonstrated a successful all-electrical spin injection and detection scheme in lateral semiconductor devices using (Ga,Mn)As/GaAs spin Esaki diode structures as spin aligning contacts. The experiments were performed in a non−local configuration, i.e., without a charge current flowing between injector an detector contacts.
In this paper we explore a possibility of an observation of a local spin-polarized charge current between source an drain in similar devices. According to Fert et al.[2] a local spin valve (SV) signal is proportional to (ρNλsf/rb)· (λsf/L), where ρN, λsf are, respectively, the resistivity and spin diffusion length in the semiconducting channel, rb is the unit area interface resistance and L a source-drain separation. Taking advantage of the relatively low value of rb in Esaki diode contacts (∼ 10−8 Ω · m2) in our devices, we optimize the latter in order to obtain a measurable local SV signal. The optimization involves (i) increasing a spin diffusion length of the semiconductor channel by lowering its doping and (ii) decreasing the source-drain distance.
[1] M. Ciorga et al., Phys. Rev. B 79, 165321 (2009)
[2] A. Fert et al. IEEE Trans. on Electr. Dev. 54, 921 (2007).