Quantum dots - the perfect computer memory?

Researchers in Germany have been exploring the suitability of self-assembled arrays of quantum dots for nonvolatile storage. A quantum dot is a small clump of atoms that is confined in a way that restricts the motion of the electrons, making the whole thing act like a single atom. The properties of the dot can be modified by changing the size of the clump or the constituent atoms.

In the quantum dot-based storage array, the researchers have been looking at the constituent atoms, trying out silicon and germanium, and more complicated mixtures of gallium, indium, arsenide, aluminum, and antimony (for those of you keeping count, these are III-V materials). Experimentally, they have found that quantum dots can have access times of around 10ns, faster than the current generation of RAM, and they require a refresh rate as low as 0.7Hz. Further calculations show that more suitable combinations would result in a storage time of one million years while maintaining the same access time.