The all-metal spin transistor

An entirely new kind of switching device is fabricated entirely from metals. The three-layer, three-terminal spin transistor behaves somewhat like a semiconductor bipolar transistor; though the physical operating principles differ. The emitter and collector layers of the spin transistor are ferromagnetic films. The base layer is a nonmagnetic metal, such as gold, copper, or silver. Being all-metal the device can be made much smaller than semiconductor transistors-less than 0.1 micrometer on a side. Although still a technological infant, the device has the electrical properties required by memory cells, current amplifiers, and logic circuits. A computer made only of metals seems quite possible.<>