Researchers develop a light source that produces two entangled light beams

Scientists are increasingly studying quantum entanglement, which occurs when two or more systems are created or interact in such a manner that the quantum states of some cannot be described independently of the quantum states of the others. The systems are correlated, even when they are separated by a large distance. The significant potential for applications in encryption, communications and quantum computing spurs research. The difficulty is that when the systems interact with their surroundings, they almost immediately become disentangled.