Fast quantum computer bit is created

ANN ARBOR, Mich., Aug. 21 (UPI) -- U.S. scientists say they have made the fastest quantum computer bit created, demonstrating the advantage of the qubit over the conventional bit.

Researchers at University of Michigan, U.S. Naval Research Laboratory and the University of California-San Diego said they used lasers to create an initialized quantum state of the solid-state qubit at rates of about a gigahertz per second.

A conventional bit can be a 0 or a 1, while a quantum bit, or qubit, can be both at the same time, the researchers said.

Physics Professor Duncan Steel, doctoral student Xiaodong Xu and their colleagues used lasers to coherently, or stably, trap the spin of one electron confined in a single semiconductor quantum dot. A quantum dot is similar to a transistor in a conventional computer.

"We are the first to show that you can do this to a single electron in a self-assembled quantum dot," Steel said. "If you're going to do quantum computing, you have to be able to work with one electron at a time."

A paper describing the complex research is available in the early online edition of the journal Nature Physics and will appear in print at a later date.