Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 14: Spintronics: Transport and Theory
HL 14.4: Vortrag
Montag, 7. März 2016, 15:30–15:45, H13
Hanle spin precession in two-dimensional electron gas — •Martin Oltscher, Josef Loher, Dieter Schuh, Mariusz Ciorga, Dominique Bougeard, and Dieter Weiss — University of Regensburg, 93040 Regensburg, Germany
Effective electrical spin injection into two-dimensional electron systems is prerequisite for many new functionalities in possible spintronic devices, with a Datta-Das spin field effect transistor being a primary example. We have recently demonstrated efficient spin injection into high mobility 2DEG confined in the inverted (Al,Ga)As/GaAs structure. In this contribution we present the results of further investigations on that system, focusing on nonlocal Hanle measurements of spin precession in an out-of-plane magnetic field. We observe that not only the amplitude of the precession signal but also its full-width-at-half-maximum strongly changes with the bias voltage V3T applied across the injector. Narrowest curves are observed in the region of the enhanced signal for negative bias. In the region of low bias -0.1 V < V3T < 0.1 V, on the other hand, no precession curves are observed. What is more, spin life time values extracted from the measurements (∼ 23 ns for the narrowest curve) differ by orders of magnitude from the values expected for 2DEGs and from the value of 24 ps extracted earlier from spin-valve measurements. We discuss the results in connection to dynamic nuclear polarization effects in the system, which are known to narrow the experimental Hanle curves. The work has been supported by German Science Foundation (DFG) through the project SFB689.