Three-Color Entanglement

Abstract

Entangling Rainbows Quantum mechanical entanglement is at the heart of quantum information processing. In the future, practical systems will contain a network of quantum components, possibly operating at different frequencies. Coelho et al. (p. 823 , published online 17 September) present a technique that can entangle light beams of three different frequencies. The ability to swap entanglement between different light fields should prove useful in advanced quantum information protocols on systems comprising different operating frequencies.