Experiment (IMAGE) University of the Witwatersrand Caption This is a schematic of the experiment. Four photons are created, one pair from each entanglement source (BBO). One from each pair (B and C) are brought together on a beam splitter. When all four photons are measured in together one finds that photons A and D, which previously where independent, are now entangled. Credit Wits University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.