Breakthrough in quantum networks stores data across 83 frequency channels
A team of researchers, including Hiroki Tateishi, Daisuke Yoshida, and Tomoki Tsuno, has achieved a major step forward in quantum communication. They successfully stored broadband photons across 83 separate frequency channels using a rare-earth crystal. This breakthrough could significantly boost the capacity of future quantum networks.
The team developed an integrated system combining a cavity-enhanced photon-pair source with an atomic frequency comb memory. At its core lies a Pr³⁺:Y₂SiO₅ crystal, which operates at telecom wavelengths—specifically within the C-band. This range is ideal for long-distance communication, as it minimises signal loss in optical fibres.
Their experiments demonstrated storage and distribution of narrowband telecom photon pairs across up to 83 distinct frequency modes, spaced 123 MHz apart. Compared to single-mode operation, the system achieved a 33-fold increase in stored information, measured by the coincidence rate. The researchers also confirmed strong nonclassical correlations after storage, proving the system’s reliability for preserving quantum states.
Frequency multiplexing plays a key role in this advance. By packing multiple channels into a single system, the approach enhances entanglement distribution rates. This scalability offers a practical route toward building high-capacity quantum networks for secure communication and distributed computing.
The results confirm that the integrated photon source and quantum memory can handle high-frequency multiplicity efficiently. The compatibility with existing fibre infrastructure further strengthens its potential for real-world applications. This development brings large-scale quantum networks one step closer to practical use.
