Postselected versus nonpostselected quantum teleportation using parametricdown-conversion - art. no. 042304

We study the experimental realization of quantum teleportation as performed by Bouwmeester et al. [Nature (London) 390, 575 (1997)] and the adjustment s to it suggested by Braunstein and Kimble [Nature (London) 394, 841 (1998) ]. These suggestions include the employment of a detector cascade and a rel ative slow-down of one of the two down-converters. We show that coincidence s between photon pairs from parametric down-conversion automatically probe the non-Poissonian structure of these sources. Furthermore, we find that de tector cascading is of limited use, and that modifying the relative strengt hs of the down-conversion efficiencies will increase the time of the experi ment to the order of weeks. Our analysis therefore points to the benefits o f single-photon detectors in non post selected-type experiments, a technolo gy currently requiring roughly 6 degrees K operating conditions.