Abstract:

An InGaAs quantum well was made as a 2DEG (two dimensional electron gas) with structure inversion asymmetry (SIA). Rashba spin-orbit coupling in such a system was revealed by Shubnikov-de Haas (SdH) oscillation from its beating pattern. Current in the plane of the 2DEG can induce electron spin polarization oriented perpendicular to the current direction, and the spin can be detected by Kerr effect. That is a possible way of creating spin polarization in a semiconductor without either applying magnetic field, or using dilute magnetic materials.
Such current induced electron spin polarization can be further taken as an approach to create spin source for a spintronic device. Furthermore, we have achieved converting a spin current in such a Rashba system into a measurable electric current, which is of great importance in spin detection or making the drain for a spin FET, as proposed by Datta & Das.
Other approaches relevant to spintroincs devices by using asymmetric spin relaxation in a Rashba system, or using spin filter in a Dresslehaus system, will also be discussed.
 
 
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