Key points are not available for this paper at this time.
Practical quantum networks require interfacing quantum memories with existing channels and systems that operate in the telecom band. Here we demonstrate low-noise, bidirectional quantum frequency conversion that enables a solid-state quantum memory to directly interface with telecom-band systems. In particular, we demonstrate conversion of visible-band single photons emitted from a silicon-vacancy (SiV) center in diamond to the telecom O band, maintaining low noise (g2(0)0.1) and high indistinguishability (V=89±8%). We further demonstrate the utility of this system for quantum networking by converting telecom-band time-bin pulses, sent across a lossy and noisy 50-km deployed fiber link, to the visible band and entangling them with a diamond quantum memory with fidelity F≥87±2.5%. These results demonstrate the viability of SiV quantum memories integrated with telecom-band systems for scalable quantum networking applications. Published by the American Physical Society 2024
Bersin et al. (Mon,) studied this question.