Science: Entanglement, a seemingly impossible link between distant particles, is key to physicists’ plans for revolutionary quantum computers and uncrackable quantum communications systems. Creating entangled pairs of light particles, or photons, is a delicate business. Now, physicists from Japan and the United Kingdom have found a way to do it by simply passing ordinary photons through a novel optical filter.
“This is pretty cool,” says Alan Migdall of the National Institute of Standards and Technology in Gaithersburg, Maryland. “I haven’t seen an approach like this before.” Still, he and others say it’s too soon to tell whether the new method, described on page 483 in Science, will outshine techniques that generate pairs of photons entangled from “birth.”
Modeling the shapes of tree branches, neurons, and blood vessels is a thorny problem, but researchers have just discovered that much of the math has already been done.