IBM developing storage device of just 12 atoms

Researchers at IBM have stored and retrieved digital 1s and 0s from an array of just 12 atoms, pushing the boundaries of the magnetic storage of information to the edge of what is possible.

The findings, being reported Thursday in the journal Science, could help lead to a new class of nanomaterials for a generation of memory chips and disk drives that will not only have greater capabilities than the current silicon-based computers but will also consume significantly less power. And it may offer a new direction for research in quantum computing.

"Magnetic materials are extremely useful and strategically important to many major economies, but there aren't that many of them," said Shan X Wang, director of the Center for Magnetic Nanotechnology at Stanford University. "To make a brand new material is very intriguing and scientifically very important."

Until now, the most advanced magnetic storage systems have needed about 1 million atoms to store a digital 1 or 0. The new achievement is the product of a heated international race between two elite physics laboratories to explore the properties of magnetic materials at a far smaller scale.

Last May, a group at the Institute of Applied Physics at the University of Hamburg in Germany reported on the ability to perform computer logic operations on an atomic level.

The group at IBM's Almaden Research Center here, led by Andreas Heinrich, has now created the smallest possible unit of magnetic storage by painstakingly arranging two rows of six iron atoms on a surface of copper nitrite atoms. The cluster of atoms is described as anti-ferromagnetic - a rare quality in which each atom in the array has an opposed magnetic orientation. (In common ferromagnetic materials like iron, nickel and cobalt, the atoms are magnetically aligned.)

Under the laboratory's founder, Don Eigler, IBM has explored the science of nanomaterials far smaller than the silicon chips used in today's semiconductors. Eigler recently retired from the company but is a co-author of the Science paper.

The researchers now use a scanning tunneling microscope, which looks like a giant washing machine festooned with aluminum foil, not only to capture images of atoms but to reposition individual atoms - much the way a billiard ball might be moved by a pool cue with a sticky tip.

Although the research took place at temperatures near absolute zero, the scientists wrote that the same experiment could be done at room temperature with as few as 150 atoms.

As part of its demonstration of the anti-ferromagnetic storage effect, the researchers created a computer byte, or character, out of an individually placed array of 96 atoms. They then used the array to encode the IBM motto "Think" by repeatedly programming the memory block to store representations of its five letters.