New theory on spintronics replaces need for magnets

Physicists at the U.S. Department of Energy's Argonne National Laboratory have devised a potentially groundbreaking theory demonstrating how to control the spin of particles without using superconducting magnets.

"Our research illuminates a new pathway for generating and manipulating the spin in semiconductors," stated Roland Winkler Physicist at the U.S. Department of Energy's Argonne National Laboratory. "This is important, because the use of bulky superconducting magnets would be impractical in most devices."

The physicists theorize that spin can be induced and manipulated by running a current through gallium arsenide, a common semiconductor, in what is known as spin-3/2 hole systems, which previously have been little studied. Hole systems are "missing electrons," while the fraction 3/2 refers to the magnitude of the spin. Spin-3/2 hole systems are created in semiconductors by "doping" — introducing impurities that have one less electron compared to the host material.