Patent ID: 8618590

Claim:
A spin transistor comprising: a first ferromagnetic layer; a second ferromagnetic layer; a semiconductor layer between the first and second ferromagnetic layers; and a gate electrode on or above a surface of the semiconductor layer, the surface being between the first and second ferromagnetic layers, wherein one of the first and second ferromagnetic layers has an invariable magnetization and the other has a variable magnetization, wherein data are stored by a relation of magnetization directions of the first and second ferromagnetic layers, wherein electrons flow from the first ferromagnetic layer to the second ferromagnetic layer in a read operation, and wherein the first ferromagnetic layer comprises a ferromagnet which has a first minority spin band located at a high energy side and a second minority spin band located at a low energy side, and has a Fermi level in an area of the high energy side higher than a middle of a gap between the first and second minority spin bands.