On-demand production of entangled photon pairs via quantum-dot biexciton   control
  A pulsed laser scenario, designed to prepare an appropriately chosen self-assembled quantum dot with 100% population in a biexciton state, is proposed. The ensuing radiative emission would provide a near perfect (99.5%) high rate, on-demand, source of entangled photons. 
Guy Bensky, Selvakumar V. Nair, Harry E. Ruda, Shubhrangshu Dasgupta,   Gershon Kurizki and Paul Brumer
quant-ph