Research lays foundation for new era of electronics

Physicists from the Hitachi Cambridge Laboratory, the University of Cambridge and other institutes have successfully developed technology to enable the control and detection of spin current in a similar way to electric current.

Semiconductor electronic devices such as those used for information processing and data storage are based on detecting a basic attribute of an electron, its "charge". The technology developed uses a more recent concept based on another basic attribute, the electron’s elementary magnetic moment, the so-called "spin," and is opening the door to a new era of spintronics. The results of this study were published .

Andy Irvine, one of the researchers on the project, from the Cavendish Laboratory, commented on their findings: "Conventional semiconductor chips use electronic charge as a means of storing and passing digital information, but this approach runs into fundamental problems as devices get smaller. Using instead the ’spin’ property of the electron allows us to imagine a new breed of device, with the potential for long data storage times, small size and low power, as well as strategies to realise very new concepts like quantum computing.

"A drawback of using spin in semiconductors is that the transfer, detection and manipulation of spin information has always been very difficult to achieve, typically relying on inefficient magnetic contacts. We have found ways to produce a pure spin current in non-magnetic devices using laser light, to sustain the spin signal during transit, to manipulate it just by applying a voltage, and to detect it electrically. We get spin-logic operation without conventional current flow. For high-volume information processing applications our technique is not really practical, but it allows us to prove the spin-transistor principle twenty years after it was first proposed and provides a good grounding for the next generation of devices."

Sixty years after the development of the transistor by William Shockley in 1948, the operation of solid state electronic devices has utilised physical principles to electrically manipulate and measure the charge of electrons. The new science and technology field of spintronics, which is based on another basic attribute of an electron, its elementary magnetic moment or "spin," has been an area which has attracted high expectations as its development could open the way to new low-power electronics, hybrid electric-magnetic systems and completely new functionalities.