Researchers witness quantum interference and entanglement between photons from sources 150 million km apart—the Sun and a quantum dot in their lab.
The team managed to generate entangled states between photons from the two sources and demonstrated that such states clearly violated a Bell inequality, a test that unambiguously reveals nonlocal correlation between particles. That suggests sunlight could be used as an independent light source in certain quantum encryption schemes.
This research is published in Physical Review Letters. (APS Physics)