Taking the Hall Effect for a Spin

The Hall effect is a phenomenon where a current is produced in the direction perpendicular to an electric field applied to a solid. Discovered in its original form 126 years ago, new variants of the Hall effect in the absence of a magnetic field that involve the spin rather than the charge of electrons continue to be discovered. In their Perspective, Inoue and Ohno discuss recent work in which two groups have recently reported the existence of spin Hall currents. The exact mechanisms and behavior are still uncertain, but the results may have practical significance to spintronics, a new generation of electronic devices based on manipulation and control of electron spin.