Room-temperature spin Hall effect

In the regular Hall effect, electrons that move longitudinally under the force of an applied electric field through a sample will, if exposed to a vertically oriented magnetic field, be deflected slightly to one side. Two years ago, physicists showed that a kind of Hall effect in a vertical electric field could produce a net pileup of spins at the edge of the sample, even though no pileup of electric charges would occur (see Physics Today, February 2005, page 17). Physicists at the University of California, Santa Barbara, with collaborators from the Pennsylvania State University, now have used a sample of zinc selenide—a nonmagnetic II–VI semiconductor—to demonstrate both electrically induced spin polarization and the segregation of electrons based on spin. Using a diagnostic technique called Kerr rotation spectroscopy, the researchers showed that spins of opposite sign congregated on opposites sides of the sample, that the effect persists all...