It might be some way off but computers users in the future could take data off a disk drive and move it into the nucleus of an atom.

Scientists have demonstrated what is being called the "ultimate miniaturisation of computer memory," storing data for nearly 2 seconds in the nucleus of an atom. This is a key step in the development of quantum computers, according to the National Science Foundation (NSF).

Using a new technique, an international team of scientists "demonstrated that information stored in the nucleus has a lifetime of about 1 ¾ seconds," said the NSF, describing a new study in the journal Nature. "This is significant because before this technique was developed, the longest researchers could preserve quantum information in silicon was less than one-tenth of a second. Other researchers studying quantum computing recently calculated that if a quantum system could store information for at least 1 second, error correction techniques could then protect that data for an indefinite period of time."

The scientists, from Princeton University, Oxford University and the US Department of Energy, broke the 1-second barrier with a system that uses the electron and nucleus of a phosphorous atom embedded in a silicon crystal. The electron and nucleus each behaved like tiny "quantum magnets" that could store quantum information, but the instability of the electron made it unsuitable for storing information. "To overcome the problem, researchers moved the information into the nucleus where it survived much longer," the NSF states. Data in the electron cloud, which is a million times bigger than the nucleus, can be manipulated, thus serving as a "middle-man" between the nucleus and the outside world, researchers say.

"Nobody really knew how long a nucleus might hold quantum information in this system," Princeton researcher Steve Lyon said. "With crystals painstakingly grown ... and very careful measurements, we were delighted to see memory times exceeding the [one-second] threshold."

Under the theory of quantum mechanics, atoms and other objects can exist in multiple states, literally being in two places at once. In quantum computing, each individual piece of information could thus have more than one value simultaneously.