Scientists turn sunlight into quantum entanglement

Researchers from the University of Ottawa and the Max Planck Institute for the Science of Light created polarization entanglement of photons using sunlight instead of a laser for the first time. In an outdoor experiment the state was 94% close to perfectly entangled, and correlations violated Bell's inequality.

• Sunlight was concentrated with a Fresnel lens and directed into a crystal via a glass cone
• Entanglement from sunlight matched the ideal state by 94%
• Photon correlations violated Bell's inequality, confirming quantum nature
• The technology could cut energy costs of quantum communication and computing