Laser beams are entangled in space
A breakthrough in laser entanglement could allow optical measurements to beat the diffraction limit.
Physicists in Australia and France have worked out a way to entangle the spatial properties of two laser beams for the first time. Such entangled beams could someday be used to make optical measurements at higher degrees of accuracy than possible with a single beam and even transmit large quantities of quantum information (Science 321 541).
In the weird world of quantum mechanics, entanglement means that particles can have a much closer relationship than allowed by classical physics. For instance, two photons can be...