Challenge for chip designers of future

To build the computer chips of the future, designers will need to understand how an electrical charge behaves when it is confined to metal wires only a few atom-widths in diameter. Now, a team of physicists at McGill University, in collaboration with researchers at General Motors R&D, have shown that electrical current may be drastically reduced when wires from two dissimilar metals meet. The surprisingly sharp reduction in current reveals a significant challenge that could shape material choices and device design in the emerging field of nanoelectronics. The size of features in electronic circuits is shrinking every year, thanks to the aggressive miniaturization prescribed by Moore's Law, which postulated that the density of transistors on integrated circuits would double every 18 months or so. This steady progress makes it possible to carry around computers in our pockets, but poses serious challenges. As feature sizes dwindle to the level of atoms, the resistance to current no longer increases at a consistent rate as devices shrink; instead the resistance "jumps around," displaying the counterintuitive effects of quantum mechanics, says McGill Physics Peter Grütter. "You could use the analogy of a water hose," Grütter explains.