Non post-selected indistinguishable single photons generated by a   quantum dot under resonant excitation
  We report on two-photon interferences from highly indistinguishable single photons emitted by a quantum dot. Stricly resonant excitation with picosecond laser pulses allows coherent state preparation with a signifi- cantly increased coherence time (T2 \sim 1 ns) and reduced lifetime (T1 \sim 650 ps), as compared to a non-resonant excitation scheme. Building-up the Hong-Ou-Mandel dip without post-selection of the interfering photons, visi- bilities greater than 70 % have been observed. Near-unity indistinguishable photons could be achieved for every dot if charge noise is controlled. Indeed, the remaining decoherence mechanism is likely due to the fluctuating electrostatic environment of the dots. 
L\'eonard Monniello, Antoine Reigue, Richard Hostein, Aristide   Lemaitre, Anthony Martinez, Roger Grousson, and Valia Voliotis
cond-mat.mes-hall