Now, though, researchers have shrunk the technology down to less than the width of a human hair, small enough to squeeze onto a chip.

Photon entanglement is one of the odder properties of quantum physics, but it promises a lot for computing -- if one photon can instantly affect another no matter how far away it is, you could make super-speedy computers and communications that aren't easily limited by physical distances. It hasn't been easy to get entanglement tech down to a manageable size, however, and that's where Italy's Università degli Studi di Pavia might just come to the rescue. Its researchers have developed a tiny emitter that could pump out entangled photons as part of an otherwise ordinary silicon chip. The device, which uses a ring shape to both rope in and emit light, measures just 20 microns across.