Study for realization of spin-polarized field effect transistor in In0.75Ga0.25As/In0.75Al0.25As heterostructure

For realization of the spin-polarized field effect transistor (spin-FET), we investigated a gated modulation of spin-orbit interaction and a spin-injection from a ferromagnetic metal (FM) to a two-dimensional electron gas (2DEG). Prepared samples were an In0.75GaO0.25As/In0.75Al0.25As modulation-doped narrow-gap heterojunction grown by molecular beam epitaxy (MBE). For the determination of spin-orbit interaction parameter, alpha we measured Shubnikov-de Haas (SdH) oscillations at 1.5 K. We confirmed a modulation of D when a gate voltage was applied. We also carried out spin-injection experiments using a multi-terminal geometry sample, which had two different widths Ni40Fe60 electrodes. We observed a spin-valve like effect in a source-drain resistance of similar to 0.1% as well as a resistance hysteresis behavior of similar to 12% in non-local geometry below 20 K. These results are the first step to realize an active spintronic device, such as spin-FET. (C) 2002 Elsevier Science B.V. All rights reserved.