The door to practically building tomorrow's quantum computers has opened a little wider, with researchers crafting a wire just four atoms wide and one atom high that is able to conduct current just like traditional copper wiring. The team, made up of participants from Purdue University, the University of New South Wales, and Melbourne University, created the wire by etching a microscopic line into a piece of silicon and lining up phosphorous atoms along it. Previous efforts to create wires on the nanometer scale had suggested that resistivity increases as sizes shrink, rendering them impractical for the very thing they're intended for: conducting current. The new atomic-level wire demonstrates none of these issues.
The creation could provide a way to connect atomic-level components to one another in the practical construction of quantum computers. It may also extend the life of one of the semiconductor industry's favorite truisms: Moore's law. That concept, which suggests that the number of transistors that can be placed on an integrated circuit doubles every two years, will eventually face physical size contraints. With innovations like the new wire, however, it may be able to continue all the way down to the atomic level.