Physics World
Atomic entanglement on a grand scale
Eugene Simon Polzik
Abstract
QUANTUM entanglement is one the weirdest features of quantum mechanics and is at the heart of most of the paradoxes in quantum theory. Erwin Schrödinger considered it to be the most profound characteristics of quantum mechanics and Albert Einstein called it spooky. Entanglement is an attribute that links two or more quantum systems as one and allows particles with two distinct quantum states to have a much closer relationship than classical physics permits. For instance it is possible to create pairs of photons that have their polarizations entangled: if the first photon is circularly polarized in a right-handed sense, then the second photon is always polarized in a left-handed sense, and vice versa.