Authors: Xiao-Song Ma; Thomas Herbst; Thomas Scheidl; Daqing Wang; Sebastian Kropatschek; William Naylor; Bernhard Wittmann; Alexandra Mech; Johannes Kofler; Elena Anisimova; Vadim Makarov; Thomas Jennewein; Rupert Ursin; Anton Zeilinger Journal: Nature Date: 2012-09-13 Impact factor: 49.962