Phys.org May 25, 2022
Researchers in Germany have created a scalable star-shaped quantum-key-distribution (QKD) optical-fiber network using WDM of broadband photon pairs to establish key exchange between multiple pairs of participants. They demonstrated simultaneous bipartite key exchange between any possible combination of participants and showed that the quantum bit error rate (QBER) itself can be used to stabilize the phase in the interferometers by small temperature adjustments. The key distribution is insensitive to polarization fluctuations in the network, enabling key distribution using deployed fibers even under challenging environmental conditions. They demonstrated that the network could be extended to 34 participants by using a standard arrayed-waveguide grating for WDM and reconfigurable network connections are possible with a wavelength-selective switch. The system is scalable and has a simple design of the receiver modules. According to the researchers a secure communication infrastructure on a metropolitan scale can be established…read more. Open Access TECHNICAL ARTICLEÂ
The scheme for time-bin entanglement quantum key distribution with the BBM92 protocol. Credit: PRX Quantum 3, 020341, 24 May 2022Â