NIST Achieves Record-Low Error Rate for Quantum Information Processing with One Qubit

From NIST Tech Beat: August 30, 2011
Contact: Laura Ost
303-497-4880

Thanks to advances in experimental design, physicists at the National Institute of Standards and Technology (NIST) have achieved a record-low probability of error in quantum information processing with a single quantum bit (qubit)—the first published error rate small enough to meet theoretical requirements for building viable quantum computers.
A quantum computer could potentially solve certain problems that are intractable using today's technology, even supercomputers. The NIST experiment with a single beryllium ion qubit, described in a forthcoming paper,* is a milestone for simple quantum logic operations. However, a working quantum computer also will require two-qubit logic operations with comparably low error rates.
"One error per 10,000 logic operations is a commonly agreed upon target for a low enough error rate to use error correction protocols in a quantum computer," explains Kenton Brown, who led the project as a NIST postdoctoral researcher. "It is generally accepted that if error rates are above that, you will introduce more errors in your correction operations than you are able to correct. We've been able to show that we have good enough control over our single-qubit operations that our probability of error is 1 per 50,000 logic operations."
The NIST experiment was performed on 1,000 unique sequences of logic operations randomly selected by computer software. Sequences of 10 different lengths, ranging from one to 987 operations, were repeated 100 times each. The measured results were compared to perfect theoretical outcomes. The maximum length of the sequences was limited by the hardware used to control the experiment.

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