IBM researchers this week announced they've made major strides in nanotechnology by studying how to build storage and other computing devices out of components no bigger than a few atoms or molecules.
Researchers at the company's Almaden Research Center in San Jose, Calif., report in Science that magnetic anisotropy could eventually be used to store information in individual atoms, paving the way to pack as much as 150 trillion bits of data per square inch, 1,000 times more than current data storage densities. In other words, the ability to store data in individual atoms could lead to devices capable of storing the equivalent of 30,000 movies in a device the size of an iPod.
Anisotropy measures how far a magnet's pull reaches in any single direction. "Every atom has a magnet inside," says Cyrus Hirjibehedin, a researcher at the Almaden lab, noting that the magnetic orientation of an atom is called its "spin." "We want to understand the properties of an atom and were able to measure the anisotropy for a single atom in a particular environment."
IBM Almaden researchers used the company's scanning tunneling microscope to manipulate individual iron atoms and arrange them with atomic precision on a specially prepared copper surface; scientists previously were unable to measure the magnetic anisotropy of a single atom. IBM used the microscope to determine the orientation and strength of the magnetic anisotropy of each iron atom.
"Now we have a means for understanding anisotropy," says Andreas Heinrich, manager of Almaden's Scanning Tunneling Microscopy lab. The next step, he says, is fashioning a system in which the atom's spin is stable enough to be used for data storage--something that scientists may achieve in several years or, Heinrich says, may not even be possible. "Our job is to jump ahead," he adds. "We hope to make a drastic change rather than incremental improvements."
Another Science report describes research by scientists at IBM's Zurich Research Laboratory in Switzerland on ways to use a single molecule to perform many of the same functions now carried out by silicon. The study indicates that it's possible to turn a single molecule into a switch without disrupting its outer shell--a significant step toward building computing elements at the molecular scale that are vastly smaller and faster, and use less energy than today's computer chips and memory devices.
Switches inside computer chips turn the flow of electrons on and off and, when put together, form the logic gates that make up the electrical circuits of the computer processors. Having ever-smaller switches allows the circuits to be shrunk to ever-tinier sizes, making it possible to crowd more circuits into a processor, boosting speed and performance.
Researchers at IBM and elsewhere previously demonstrated switching within single molecules, but the molecules would change their shape when switched, making them unsuitable for building logic gates for computer chips or memory elements.
Next up for the Zurich research team: building a series of these molecules into a circuit, and then figuring out how to link them to make a molecular chip.