Engineers at the University of Utah say they've developed a new material that may lead to computers that operate at super-fast computing speeds without the danger of overheating.
They describe the material as a "topological insulator," consisting of a layer of metal applied atop a silicon semiconductor.
The material behaves as an insulator internally but can conduct electricity on its outside surface, the researchers report in the Proceedings of the National Academy of Sciences.
Topological insulators are a group of material known for almost 10 years and considered ideal for speeding up computers.
The challenge, the researchers noted, has been to create one that provides a large energy gap, defined as the level of energy needed for electricity to be conducted by electrons in any given material.
A material with a bigger gap would allow electricity to flow on a material's surface rather than in its interior so a computer could operate at high speeds at room temperature without overheating while still remaining stable.
Utah engineering Professor Feng Liu and his colleagues discovered that the metal bismuth deposited atop silicon yielded a topological insulator with a large energy gap.
The bismuth layer was bonded atomically to the silicon, but isolated electronically, creating a significant but stable energy gap.
"It has the largest energy gap that was ever predicted. It makes room-temperature applications a possibility for topological insulator-based devices or computers," Liu says.
And, they emphasize, creating the material can be done cost-effectively and can be easily integrated with existing silicon semiconductor manufacturing procedures.
"We can put it on silicon so it can be married or combined with the existing semiconductor technology," Liu says. "This is very important. It makes it more experimentally feasible and practically realistic."
The discovery could be yet another step on the way to quantum computers and fast spintronic devices, the researchers say, and allow both to operate efficiently at room temperature.
Quantum computers, still only on the drawing board, would harness the quantum behavior of particles of matter and light -- able to simultaneously exist in different locations -- to provide computing speeds billions of times greater than existing conventional computers can manage.
Spintronics is another coming technology that utilizes the spin of electrons, instead of their charge, to store and transmit data in electronic circuitry in electronic devices including computers.
The spinning property of the electrons turns them into atomic-scale magnets that can encode information.
The research by Liu and his team was funded in part by the National Science Foundation and the U.S. Department of Energy.
