Heralded Distribution of Single-Photon Path Entanglement
Patrik Caspar, E. Verbanis, Enky Oudot, Nicolas Maring, Farid Samara, Misael Caloz, Matthieu Perrenoud, Pavel Sekatski, Anthony Martin, Nicolas Sangouard, Hugo Zbinden, Rob Thew
Abstract
We report the experimental realization of heralded distribution of single-photon path entanglement at telecommunication wavelengths in a repeater-like architecture. The entanglement is established upon detection of a single photon, originating from one of two spontaneous parametric down-conversion photon pair sources, after erasing the photon's which-path information. In order to certify the entanglement, we use an entanglement witness which does not rely on postselection. We herald entanglement between two locations, separated by a total distance of 2 km of optical fiber, at a rate of 1.6 kHz. This work paves the way towards high-rate and practical quantum repeater architectures.