Spin Hall effect for detection of spin-currents -- Realization of a Spin transistor

The realization of a viable semiconductor transistor and information processing devices based on the electron spin has fueled intense basic research of three key elements: injection, detection, and manipulation of spins in the semiconductor microchannel. The inverse spin Hall effect (iSHE) detection of spins manipulated by a gate electrode [1] has recently led to the experimental demonstration of a spin transistor device. [2] Here, the spin injection into a 2-dimensional electron gas (2DEG) was done optically in the depletion layer of a reverse biased pn-junction. [3] The iSHE detection is also used for electrical spin injection from a Fe electrode into a lateral GaAs channel combined with a simultaneous non-local spin valve measurement [4-10]. The spins in the channel are manipulated via the Hanle spin precession induced by an applied magnetic field and via a drift of electrons induced by an applied electric field. The output spin signal is suppressed or enhanced depending on the applied electrical bias rendering the device to a spin transitor different from the Datta Das concept. [11] \\[4pt] [1] S. Datta and B. Das, Appl. Phys. Lett. 56, 665 (1990). \\[0pt] [2] J. Wunderlich, et al., Science 330,1801 (2010). \\[0pt] [3] J. Wunderlich, et al., Nature Phys., 5, 675 (2009). \\[0pt] [4] X. Lou, Nature Phys. 3, 197 (2007). \\[0pt] [5] M. Ciorga, et al., Phys. Rev. B 79, 165321 (2009). \\[0pt] [6] C. Awo-Affouda, et al., Appl. Phys. Lett. 94, 102511 (2009). \\[0pt] [7] M. K. Chan, et al., Phys. Rev. B 80, 161206(R) (2009). \\[0pt] [8] G. Salis, et al., Phys. Rev. B 80, 115332 (2009). \\[0pt] [9] G. Salis, et al., Phys. Rev. B 81, 205323 (2010). \\[0pt] [10] E. S. Garlid, et al., Phys. Rev. Lett. 105, 156602 (2010). \\[0pt] [11] K. Olejnik, et al., submitted.