A Photon Pair Source for Quantum Repeaters

28 May 2013

Our paper ” Ultranarrowband Photon Pair Source compatible with Solid State Quantum Memories and Telecommunication Networks” has been published in Physical Review Letters. It was selected as Editors´suggestion and there is an accompanying  Viewpoint in Physics, written by Philip Hemmer. See also the web news on the ICFO website.

Figure 1APS/Alan Stonebraker

Figure 1: Illustration of the entanglement of two distant quantum memories, operating at different wavelengths, using telecom photons transmitted over an internet fiber. Operation of the photon-pair source at the wavelengths shown on the left was demonstrated in the paper. The source on the right can be constructed by the same approach and is easier to realize because the generated wavelengths are closer. In this example, entanglement is created by measurement of identical 1436 nm photons, each produced by a different photon-pair source and interfered on a 50% beam splitter.


We report on a source of ultranarrow-band photon pairs generated by widely nondegenerate cavity-enhanced spontaneous down-conversion. The source is designed to be compatible with Pr3+ solid state quantum memories and telecommunication optical fibers, with signal and idler photons close to 606 nm and 1436 nm, respectively. Both photons have a spectral bandwidth around 2 MHz, matching the bandwidth of Pr3+ doped quantum memories. This source is ideally suited for long distance quantum communication architectures involving solid state quantum memories.

Ref: Ultranarrowband Photon Pair Source compatible with Solid State Quantum Memories and Telecommunication Networks
Julia Fekete, Daniel Rieländer, Matteo Cristiani and Hugues de Riedmatten
Phys. Rev. Lett. 110, 220502 (2013), see also accompanying Viewpoint in Physics  by P. Hemmer.