The Spectral Architecture of Quantum Entanglement

Warren P. Grice, Raphael C. Pooser, Brian P. Williams

We describe a quantum repeater architecture for spectrally entangled photons based on sum frequency. The repeater, which does not require a conventional quantum memory, includes a novel scheme for re-using unconverted photons.

Chen‐Te Ma, Chih-Hung Wu

P. Tombesi

Wolfgang Tittel

Future quantum networks will require quantum repeaters to distribute entangled photons. I will present a quantum repeater architecture based on spectral multiplexing, detail system performance, and describe some recent experimental key results towards its implementation.

Alexander Kolar, Ian Chin, Conner Fong +5 more

Scalable quantum networks require the efficient generation and storage of entanglement between photonic qubits and quantum memories. Quantum repeaters based on absorptive rare-earth-ion photonic memories offer a promising route toward highly multiplexed quantum networking, but unifying spectrally matched photon sources and quantum memories within a common architecture remains a major challenge. Here we demonstrate an integrated photonic architecture for telecom photon-memory entanglement generation based on dual self-similar silicon carbide microring resonators. Connected by a fiber link, one resonator operates as an entangled photon-pair source, while the other functions as a cavity-enhanced atomic-frequency-comb quantum memory. The memory resonator reaches an ensemble cooperativity of 1.9 after hyperfine initialization and is spectrally matched to the source, enabling storage of entangled telecom photons without spectral modification. We generate and characterize photon-memory entanglement from a quantum interference visibility preserved before and after storage. Harnessing the strong source correlations and the high multimode capacity of the memory, we access high-dimensional entanglement spanning 63 temporal modes, reaching a maximum photon information efficiency of 5.1 Ebits per detected photon and a peak on-chip photon-memory entanglement rate of 5.6 kEbits per second. These results establish a route toward chip-scale quantum networking hardware operating over telecommunications infrastructure.

Manuel Aschwanden