IBM has demonstrated how to perform certain computer functions on single atoms and molecules.
Researchers at IBM’s Almaden Research Centre in California developed a technique for measuring magnetic anisotropy, a property of the magnetic field that gives it the ability to maintain a particular direction. The discovery could someday lead to processors the size of a speck of dust, the company said.
Being able to measure magnetic anisotropy at the atomic level is a crucial step toward the magnet representing the ones or the zeroes used to store data in binary computer language.
In a second report, researchers at IBM’s lab in Zurich, Switzerland, said they had used an individual molecule as an electric switch that could potentially replace the transistors used in modern chips. The company published both research reports in Friday’s edition of the journal Science.
The new technologies are at least 10 years from being used for components in commercial products, but the discoveries will allow scientists to take a large step forward in their quest to replace silicon, said IBM spokesman Matthew McMahon.
To build faster, smaller chips, IBM and other chip vendors like Intel and Advanced Micro Devices have shrunk the dimensions of chip features from 90 nanometers to 65nm in the current generation of chips, and plan to continue to 45nm and 32nm in coming years. The problem is that wires built from silicon tend to leak more electricity at each step on that scale, and will eventually reach a limit where they are no longer useful.
"Across all our areas of nanotechnology research, we’re trying to determine the new kinds of materials we can use in computing when silicon reaches its fundamental limits. The ultimate goal is molecular-level computers, but the interim products will probably be hybrids with current technology, using things like carbon nanotubes," McMahon said.
IBM defines nanotechnology as work done at a scale of 100nm or smaller. At that scale, scientists must use a tool called the scanning tunnelling microscope (STM) to photograph and manipulate individual atoms, as they did in their latest research. Their next challenge is to find a way to make these laboratory demonstrations work at room temperature, he said.
Having measured the magnetic anisotropy of a single atom, “their next step is finding atoms that can do it at stable temperatures that are suitable for storage devices. If they can find that, it’s still a decade out from commercialisation,” he said.
The Zurich researchers also developed a technique for using a molecule containing two hydrogen atoms as a switch, either on its own or with an adjacent molecule. They are now looking to apply the method to many other molecules, enabling the system to work as a collection of logic gates, the building blocks of microprocessors.
Even if the teams reach those goals, they must find a way to manufacture the systems on a large scale, instead of moving single atoms with the STM. One possibility is to use the process of self-assembly, where atoms under certain conditions will naturally form the desired shapes. In May, IBM said it had used that approach to insulate insulate the wires on a chip by creating trillions of tiny, vacuum-filled holes around each one.