Phys. Rev. Lett. 102, 046805 (2009)

Assemblies of quantum dots — blobs of a few thousand atoms — with electrons shuttling between them could form miniature low-power computing circuits that do not require transistors. But these architectures are fragile and must operate at temperatures close to absolute zero to control the interactions of the electrons they confine.

A team led by Robert Wolkow at Canada's National Institute for Nanotechnology in Edmonton, Alberta, has discovered that single silicon atoms, sitting in an electron-doped silicon lattice that is blanketed with hydrogen, provide electronic structures with better properties than quantum dots.

The atoms can be joined in assemblies much like the dots. Besides being smaller, these are much more robust to external disturbance and can tunnel electrons controllably at room temperature.