Scientists Just Used Sunlight To Pull Off a Quantum Physics Feat Once Thought Impossible

Scientists have shown that sunlight alone can generate quantum-correlated photons capable of producing “ghost images,” a feat once thought to require stable lasers. Quantum optics experiments typically rely on carefully controlled lasers to create correlated or entangled photon pairs. These photon pairs are produced through a process known as spontaneous parametric down-conversion (SPDC), in which [...]