Heralded single excitation of atomic ensemble via solid-state-based telecom photon detection

Telecom photonic quantum networks with matter quantum systems enable a rich variety of applications, such as long-distance quantum cryptography and one-way quantum computing. Preparation of a heralded single excitation (HSE) in an atomic ensemble by detecting a telecom wavelength photon having a correlation with the atomic excitation is an important step. Such a system has been demonstrated with a quantum frequency conversion (QFC) to telecom wavelength employing a Rb atomic cloud. However, the limited wavelength selection prevents the next step toward linking various kinds of matter quantum systems through long-distance fiber-based quantum communications. Here we for the first time, demonstrate HSE with a solid-state-based QFC and a detector for a telecom wavelength that will have the great advantage of the utility of mature telecom technologies. We unambiguously show that the demonstrated HSE indicates non-classical statistics by the direct measurement of the autocorrelation function. (C) 2016 Optical Society of America