Nicholas Nardelli, Dileep Reddy, Michael Grayson, Daniel Sörensen, Martin Stevens, Michael D. Mazurek, Lynden K. Shalm, Tara M. Fortier
We demonstrate the distribution of single-photon-level pulses from a mode-locked laser source over a phase-stable fiber link, achieving an optical timing jitter of less than 100 as over 10 minutes of data accumulation. This stability enables a fidelity greater than 0.998 between two stabilized 2.1 km long deployed fiber links. Building on time and frequency metrology techniques traditionally used for high-stability optical atomic clock signal distribution, we use time and frequency multiplexing to achieve an isolation of quantum and classical channels of 8×10 10 . Our results mark a necessary step towards scalable, high-rate quantum networks with a provable quantum advantage.