Japanese researchers find new "spin Seebeck effect", can be used to make a 'magnetic battery'

Eiji Saitoh of KeioUniversity in Yokohama, Japan, and his collaborators found that heating one side of a magnetized nickel-iron rod changes the arrangement of the electrons in the material according to their spins. These spins are the quantum-physics analogs of the south-north magnetic axes in bar magnets.

In the heated rod, electrons with spins that are aligned “up,” or with the material’s magnetic field, tend to prefer the warmer side, while those with spins pointing in the opposite direction, or “down,” tend to prefer the cooler side, the researchers report in the Oct. 9 Nature.

Engineers could harness this spin effect to design new devices for computer chips, Saitoh says. For example, a spintronic battery could produce spin imbalances at its two electrodes, and the chip could use that imbalance, instead of an ordinary electric current, and store information magnetically. Electric currents produce heat, but transferring information by flipping spins does not. Such spintronics devices would then cut down power consumption and operate at faster speeds without overheating.
Posted: Oct 09,2008 by Ron Mertens