On-Demand Single Photons with High Extraction Efficiency and Near-Unity   Indistinguishability from a Resonantly Driven Quantum Dot in a Micropillar
  Scalable photonic quantum technologies require on-demand single-photon sources with simultaneously high levels of purity, indistinguishability, and efficiency. These key features, however, have only been demonstrated separately in previous experiments. Here, by s-shell pulsed resonant excitation of a Purcell-enhanced quantum dot-micropillar system, we deterministically generate resonance fluorescence single photons which, at pi pulse excitation, have an extraction efficiency of 66%, single-photon purity of 99.1%, and photon indistinguishability of 98.5%. Such a single-photon source for the first time combines the features of high efficiency and near-perfect levels of purity and indistinguishabilty, and thus open the way to multi-photon experiments with semiconductor quantum dots. 
Xing Ding, Yu He, Z.-C. Duan, Niels Gregersen, M.-C. Chen, S.   Unsleber, S. Maier, Christian Schneider, Martin Kamp, Sven H...
quant-ph cond-mat.mes-hall