Discovery by UC Riverside physicists could enable development of faster computers

Roland Kawakami's lab proposes a simple technique for controlling electron spin and current flow

Sketch of a ferromagnet/semiconductor structure. When the MgO interface is very thin, spin up electrons, represented in this image with an arrow to the right, are reflected back to the... Click here for more information.

RIVERSIDE, Calif. – Physicists at UC Riverside have made an accidental discovery in the lab that has potential to change how information in computers can be transported or stored. Dependent on the "spin" of electrons, a property electrons possess that makes them behave like tiny magnets, the discovery could help in the development of spin-based semiconductor technology such as ultrahigh-speed computers.

The researchers were experimenting with ferromagnet/semiconductor (FM/SC) structures, which are key building blocks for semiconductor spintronic devices (microelectronic devices that perform logic operations using the spin of electrons). The FM/SC structure is sandwich-like in appearance, with the ferromagnet and semiconductor serving as microscopically thin slices between which lies a thinner still insulator made of a few atomic layers of magnesium oxide (MgO).

The researchers found that by simply altering the thickness of the MgO interface they were able to control which kinds of electrons, identified by spin, traveled from the semiconductor, through the interface, to the ferromagnet.