Nanophotonic Quantum Storage at Telecommunication Wavelength

Secure quantum communication over long distances is hindered by photon loss---a simple problem, complicated by the fact that quantum signals cannot be amplified without adding noise. The authors present on-chip quantum storage of light at telecommunication wavelength (around 1539 nm) for up to 10 μs, as an enabling technology for quantum repeater networks, which use distributed entanglement to overcome attenuation. High-fidelity quantum storage of light is demonstrated in a nanophotonic resonator fabricated in yttrium orthosilicate doped with erbium-167. Looking ahead, an improved resonator would yield a benchmark device on the way to scalable quantum communication networks.