Magnetic spins used to miniaturise computer chips
21 Dec 2010
University of Utah physicists stored information for 112 seconds in what may become the world's tiniest computer memory: magnetic "spins" in the centers or nuclei of atoms. Then the physicists retrieved and read the data electronically - a big step toward using the new kind of memory for both faster conventional and superfast "quantum" computers.
"The length of spin memory we observed is more than adequate to create memories for computers," says Christoph Boehme (pronounced Boo-meh), an associate professor of physics and senior author of the new study, published on 17 December in the journal Science. "It's a completely new way of storing and reading information."
However, some big technical hurdles remain: the nuclear spin storage-and-read-out apparatus works only at 3.2 degrees Kelvin, or slightly above absolute zero - the temperature at which atoms almost freeze to a standstill, and only can jiggle a little bit. And the apparatus must be surrounded by powerful magnetic fields roughly 200,000 times stronger than Earth's.
"Yes, you could immediately build a memory chip this way, but do you want a computer that has to be operated at 454 degrees below zero Fahrenheit and in a big national magnetic laboratory environment?" Boehme says. "First we want to learn how to do it at higher temperatures, which are more practical for a device, and without these strong magnetic fields to align the spins."
As for obtaining an electrical readout of data held within atomic nuclei, "nobody has done this before," he adds.
Two years ago, another group of scientists reported storing so-called quantum data for two seconds within atomic nuclei, but they did not read it electronically, as Boehme and colleagues did in the new study, which used classical data (0 or 1) rather than quantum data (0 and 1 simultaneously). The technique was developed in a 2006 study by Boehme, who showed it was feasible to read data stored in the net magnetic spin of 10,000 electrons in phosphorus atoms embedded in a silicon semiconductor.
