Spin transistor: detection and manipulation of spin transport in semiconductor

Abstract

The discovery of the GMR effect made a huge impact on the storage industry, and also more importantly, triggered new electronics, so-called spintronics. Utilizing electron’s spin degree of freedom as well as making use of their charge states opens the possibility of developing devices that could be smaller, consume less power, and have multi-functionalities. Even though there have been many successes in metal-based spintronic devices such as HDD read heads, sensors and magnetic memories, the semiconductor spintronic device which has multi-functions containing magnetic storage and semiconductor properties has yet to be developed. In this talk, I will present the realization of spin transistor of which all three components are preformed within all-semiconductor structure [1,2]. We optically injected spin-polarized carriers in a quasi-lateral two-dimensional electron-hole gas (2DE-HG) junction and studied the transport of the injected spins in the 2DEG channel by measuring spin Hall effect. We observed the precession of the spin-polarized electrons along the semiconductor channel up to tens of microns with a period of an order of micron. The precession of spin orientation is manipulated by external electric field, which is a key element of the spin transistor. We also demonstrate a spin AND logic function using the spin transistor with two gates.