Towards quantum dot arrays of entangled photon emitters
  We show that with a new family of pyramidal site-controlled InGaAsN quantum dots it is possible to obtain areas containing as much as 15% of polarization-entangled photon emitters - a major improvement if compared to the small fraction achievable by other quantum dot systems. Entanglement is attested by a two-photon polarization state density matrix and the parameters obtained from it. Emitters showing fidelities up to 0.721+-0.043 were found. 
Gediminas Juska, Valeria Dimastrodonato, Lorenzo O. Mereni, Agnieszka   Gocalinska and Emanuele Pelucchi
cond-mat.mes-hall quant-ph