K De Greve, L Yu, PL McMahon, JS Pelc, CM Natarajan, NY Kim, E Abe, S Maier, C Schneider, M Kamp, S Hoefling, RH Hadfield, A Forchel, MM Fejer, Y Yamamoto ‘Quantum-dot spin-photon entanglement via frequency downconversion to telecom wavelength’ Nature 491 421 (2012)
Letter to Nature: http://www.nature.com/nature/journal/v491/n7424/full/nature11577.html
Physics World commentary: http://physicsworld.com/cws/article/news/2012/nov/14/quantum-dots-entangled-with-single-photons