Ordinarily, a material that is magnetic stays that way. Only heat or stronger magnets can erase its magnetism. Now, however, researchers in Japan have made a material whose inherent magnetism can be turned off and on electrically. It takes just a flip of a switch, as long as the material stays ultracold.
The novel compound, a semiconductor, combines its extraordinary magnetic behavior with electronic properties well-suited for making microcircuits. That combination may lead to faster, lower-power devices for reading and writing magnetic data than those used today, scientists say. It might also help usher in microcircuits that exploit electrons' electric charges and also spin, a magnetic property of electrons (SN: 3/4/00, p. 155).
Hideo Ohno of Tohoku University in Sendai and his colleagues created a nonmagnetic compound of indium and arsenic. By adding manganese atoms to the mix, the researchers created mobile positive charges, called holes. These caused the manganese a