Field-effect transistor with spin-dependent transmission characteristics and non-volatile memory using same

A transistor comprising:

• a ferromagnetic source that is made of a half metal exhibiting a metallic band structure for one of the spins (“metallic spin band”) while exhibiting a semiconductor-like or insulator-like band structure for the other spin (“semiconductor spin band”), the half metal being a ferromagnetic body, spin-polarized conduction carriers being injected from the ferromagnetic source;
• a ferromagnetic drain that is made of a half metal and receives the spin-polarized conduction carriers injected from the ferromagnetic source;
• a semiconductor layer that is provided between the ferromagnetic source and the ferromagnetic drain, and is joined to the ferromagnetic source and the ferromagnetic drain;
• and
• a gate electrode that is formed associated with the semiconductor layer.

A transistor comprising:

• a source and a drain that are of a first conduction type, and are formed with ferromagnetic semiconductors;
• a semiconductor layer that is provided associated with the source and the drain, and has a channel of the first conduction type formed therein;
• and
• a gate electrode that is formed as opposed to the semiconductor layer.

A transistor comprising:

• a source that is formed with a first pn junction between a first ferromagnetic semiconductor and a semiconductor layer that are of different conductive types from each other;
• a drain that is formed with a second pn junction between a second ferromagnetic semiconductor and the semiconductor layer that are of different conductive types from each other;
• and
• a gate electrode that is formed associated with the semiconductor layer.

A transistor comprising:

• a ferromagnetic source that is formed with a ferromagnetic body from which spin-polarized conduction carriers;
• a ferromagnetic drain that is formed with a ferromagnetic body and receives the spin-polarized conduction carriers injected from the ferromagnetic source;
• a semiconductor layer that is provided between the ferromagnetic source and the ferromagnetic drain, and form junctions with the ferromagnetic source and the ferromagnetic drain;
• and
• a gate electrode that is formed associated with the semiconductor layer.