In a discovery with potentially wide industrial applications, IBM scientists said they had learned to move atoms around at will, allowing them to build structures one atom at a time.
To demonstrate the technique, scientists released a photograph of atoms of the element xenon rearranged into the letters "IBM." The picture was the first known example of atomic advertising.The discovery, described Wednesday in the British science journal Nature, opens the door for a wealth of future commercial applications, IBM said.
By building structures from the atoms up, semiconductor makers could cram many more electrical circuits on a single computer chip than is currently possible, scientists said.
Computers could store data at atomic densities more than 1 million times greater than now possible, they said. Scientists could create custom molecules atom-by-atom, or alter existing molecules to their own designs, they said.
The technique is still impractical for commercial use, however. So far, scientists have tried the technique only on xenon atoms and are unsure if it would work on other types of atoms.
Physicists Donald Eigler and Erhard Schweizer, working at IBM's Almaden Research Center in San Jose, Calif., uncovered the ability to move individual atoms while using a giant scanning tunneling microscope to study how atoms behave on a surface.
The scientists discovered that by bringing the tip of the microscope to within an atomic diameter or so of a xenon atom on a metal or semiconductor surface, they could create an attraction between the atom and the tip, allowing them to drag the atom along the surface.
Once the atom was where the scientists wanted it, they lifted the microscope's tip, breaking the attraction and leaving the atom in place.
To accomplish the feat, the microscope and the atoms had to be cooled with liquid helium to minus 269 degrees Celsius, just above absolute zero.
The microscope was operated by computer and housed in a special room to isolate it from vibrations as faint as a human voice and heat sources as weak as a nearby human body.
In the "IBM" logo written with xenon atoms, the individual letters were about 500,000 times smaller than those on a standard typewriter. The atoms were separated by only 50 billionths of an inch, or 13 millionths of the diameter of a human hair.
Harold Hess, a physicist with AT&T Bell Laboratories in New Jersey, said he suspected the technique would be more useful for basic research into the behavior of atoms than for commercial use.