Photon Source (IMAGE) University of Warsaw, Faculty of Physics Caption The photon source used to produce quantum states requiring description by complex numbers. Credit Source: USTC Usage Restrictions the image may only be used with appropriate caption: Source: USTC 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.