A Glimpse of Atomic-Scale Computing
IBM physicists announced a breakthrough today that demonstrates atomic-scale circuitry--millions of times smaller than today’s computer microprocessors--is feasible, and may eventually render modern electronic circuitry obsolete.
If futurists prove correct, this nanotechnology will ultimately pack the power of a supercomputer into a device so small that they could be woven into garments powered by body heat, or injected into a person’s bloodstream as super-intelligent diagnostic probes. It may also create computers that would never need to be plugged in and carry batteries that would never run out of power.
It may be many years before devices built around nanotechnology exist. But experts view the research as a critical step toward understanding how computers with millions, or even billions, of times more processing power that is known today might ultimately work. The findings are also seen as important for applying the science of nanotechnology, in which machines are built atom by atom, to practical purposes.
“Two or three years ago people said this is just a bunch of utopian scientists” promoting nanotechnology, said Paul Saffo, a director of the Institute for the Future, a think tank based in Menlo Park, Calif. “It’s no longer a question of if it’s possible, but when it’s practical.”
The IBM team has demonstrated that a molecular atomic-level circuit can work. The next key step, their scientists said, will be to develop ways to move this information as fast as computers do now.
But their research, dubbed “quantum mirage” by the IBM scientists, demonstrates that information can travel through solid substances without the benefit of wires.
This would be a drastic change from today’s microprocessors, the brains of most computerized devices, which require substantial electrical power to operate. Experts believe that nanotechnology processing would require only minute amounts of electrical power.
If today’s microprocessors are replaced by nanotechnology, it would require a complete rethinking of what computers can be used for because new devices could be made infinitely small, yet infinitely powerful.
Just as solid state transistors transformed earlier computers from room-sized behemoths into hand-held marvels, nanotechnology could create a super-intelligent, yet microscopic, devices, according to Eric Drexler, author of “Engines of Creation,” a seminal book on nanotechnology.
Some scientists believe that decades from now nanotechnology will usher in an era of ubiquitous computing in which everyday objects will have profound intelligence and the ability to anticipate and adjust to human needs.
Those days, should they ever arrive, are still far away. But the IBM experiment, which appears today as the cover story in the scientific journal Nature, may have moved them closer. The research was led by scientist Donald Eigler at IBM’s Almaden Research Center in San Jose.
“What’s new is the deliberate construction, atom by atom, of a device that has remote sensing capabilities,” said Eric Heller, professor of physics at Harvard University. “That’s something of a watershed.”
No one has come up with a scheme to make commercially viable atomic-scale devices. But the IBM study uncovers new information about the control of the electrical properties of individual atoms, making it “useful and important for exploring this possibility,” said Michael Crommie, a professor of physics at UC Berkeley who formerly worked with Eigler at IBM.
Conventional integrated circuit boards, packed with silicon chips, require a lot of power because they lose so much power as heat dissipates mostly through wiring within microprocessors. This leads to drained batteries and the need for noisy cooling fans, among other problems. The IBM study proves that information can be transferred without wires, and therefore without heat.
There may be some heat generated in the use of atomic-scale circuits, said Eigler, though it would be minute compared to the power requirements of today’s microelectronic components.
In their experiment, the IBM scientists used a scanning-tunneling microscope, a device that can measure and move individual atoms.
The scientists demonstrated an atomic-scale circuit by building on a sheet of copper an elliptical ring of pointy cobalt atoms--about 20 nanometers in length (one nanometer measures about 40 billionths of an inch). When they placed an additional cobalt atom inside the ellipse, it transmitted a “mirage” or faint duplicate, of that atom’s electrical state to appear at a second point within the ring.
The effect was similar to the behavior of waves of sound, such as “whisper spots” in elliptical rooms where sound carries unusually well. For example, a whisper at one end of the Old House of Representatives Chamber in the U.S. Capitol can be clearly heard at the other end.
So instead of information traveling as it now does through wiring on microchips, it might one day instead travel via an atom’s electrical fields.
By moving the cobalt atoms around, scientists can turn the mirage on or off--effectively transmitting information such as a “0” or a “1,” the basic structure of all digital data now used by computers.
This experiment proves that nanoscale circuits can be built without wires, but mass production of such circuits would be impractical with today’s methods.
“What we found is a pathway to be investigated,” Eigler said. “You’ve got to crawl before you can dance. We just started crawling in another direction.”
No one knows when such atomic-scale circuits could be operated at the speed of normal computer chips, though Eigler thinks it may be possible within five years.
“To get from there to a viable technology that can be manufactured and put on the market still requires so many steps that it would be inappropriate to estimate when or if this will come to the marketplace,” he cautioned.
Eigler’s work is part of a revival of IBM research. Once at the forefront of many of the industry’s breakthroughs, the company’s financial weakness in the early 1990s forced drastic cutbacks in its vaunted labs.
But in the last few years, as IBM’s fortunes have improved, so has the output of its research staff, now the largest of any corporation. In the last two years it pioneered new semiconductor technologies, established a new record for miniaturizing data-storage drives, and was awarded a record number of patents.
“They have a serious commitment to research that is unlikely to pay off in practical consequences in the career lifelines of those doing the research. That’s as basic as its gets,” said Saffo.