Sunlight used to generate quantum entanglement

Researchers have demonstrated that ordinary sunlight can be used to generate quantum entanglement between photons, providing a potentially more energy-efficient alternative to traditional laser-based methods. This breakthrough could reduce the heavy energy requirements currently associated with scaling quantum technologies.

The study, published in the journal Optica, involved a collaboration between Robert Boyd’s team at the University of Ottawa and Hanieh Fattahi’s team at the Max Planck Institute for the Science of Light. Using a new cone-shaped solar concentrator, the researchers showed that sunlight can produce entanglement comparable to laser-based methods when accounting for light bandwidth differences.

Potential applications include more accessible quantum sensors and communication networks. Specifically, the technology could allow satellites to generate secure encryption keys using abundant ambient sunlight in space, reducing the need for heavy onboard lasers and supporting hardware.