- 14 October 2004 -

GaAs device towards the spin transistor

Purdue University physicists have built a component for the development of quantum computers and spintronic devices. The researchers including Leonid P. Rokhinson have created a device that can effectively split a stream of quantum objects such as electrons into two streams according to the spin of each, herding "up" spin in one direction and “down spin" in another.

By producing such "spin-polarized" streams, the tiny device could become a key component in quantum computers, which have not yet left the drawing boards of the computer industry but are highly sought-after for their purported facility at cracking codes and searching large databases.

"For the first time, we have achieved spatial spin separation of the 'holes' in gallium arsenide, the spaces that electrons leave behind as they travel through this semiconductor," said Rokhinson, assistant professor of physics in Purdue’s School of Science,. "These holes also have spin characteristics, just as particles do, and separating them according to their spin has been a great challenge.

Producing this effect will be critical for the success of any spin-based electronic device, and this separation method could be one of the missing links necessary for the development of quantum computers and non-volatile memory devices, " said Rokhinson. "All spin-based processors require devices that can inject, detect and manipulate particles," he said.

"This device can both inject and detect them, and since we already have some knowledge about manipulating particles, it could mean that a major hurdle in the way of developing spintronics devices has been overcome."

Rokhinson said his team would be concentrating on creating a device that also could manipulate electron holes, thus accomplishing all three necessary tasks with a single component. "That would allow us to create a spin-based transistor,"