Berlin 2015 – scientific programme

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MA: Fachverband Magnetismus

MA 20: POSTER Ib

MA 20.18: Poster

Tuesday, March 17, 2015, 09:30–13:00, Poster A

Optical Detection of Electrical Spin Injection into a High Mobility 2DEG System — •Martin Buchner, Martin Oltscher, Mariusz Ciorga, Josef Loher, Dieter Schuh, Dominique Bougeard, Dieter Weiss, and Christian Back — Department of Physics, Regensburg University, 93053 Regensburg, Germany

In 1990 Datta and Das proposed a novel transistor concept, which utilizes the electron's spin as a new degree of freedom [1]. The current modulation arises from spin precession, which originates from the Bychkow-Rashba-term of spin-orbit-interaction. One key ingredient for the experimental realization of the device is spin injection into a two-dimensional electron gas (2DEG), which turned out to be a challenging task.

In this study, we demonstrate spin injection into a high mobility 2DEG, investigated by means of scanning Kerr microscopy at the cleaved edge of the sample. In detail, we investigate samples with the 2DEG confined at an (Al,Ga)As/GaAs interface; ferromagnetic (Ga,Mn)As contacts are used as spin aligners. The spatial distribution of the spins is probed by a diode laser directly underneath the injecting contact. Hanle depolarization gives a measure for the spin lifetimes.

[1] S. Datta, B. Das, Appl. Phys. Lett. 56, 665 (1990).