In a groundbreaking achievement, scientists from the University of Science and Technology of China have successfully created the world’s first memory-memory entanglement in a multi-node quantum network spanning a metropolitan area.
This significant advancement has extended the practical range of quantum entanglement networks from mere tens of meters to an impressive distance of tens of kilometers, marking an enhancement of three orders of magnitude.
The research team utilized three independent memory nodes, each equipped with an atomic ensemble quantum memory, and a photonic server that detects single photons to herald the success of entanglement generation. These memory nodes were separated by up to 12.5 kilometers, as detailed in their recent study published in Nature.
One of the remarkable outcomes of this study is the simultaneous generation of quantum entanglement between any two memory nodes. Additionally, the entangled states maintained their coherence longer than the time required for a round-trip communication between the nodes, demonstrating the robustness of the network.
Quantum entanglement, a phenomenon where the quantum states of objects are interdependent regardless of the distance separating them, is a cornerstone for the development of the future quantum internet. Transitioning from two-node experiments to large-scale multi-node setups is crucial for building comprehensive quantum networks.
A Nature peer reviewer commented that this achievement marks \"a new stage of quantum internet research,\" paving the way for the development of future large-scale quantum networks that could revolutionize computing and long baseline interferometry.
Reference(s):
Chinese scientists achieve multi-node entanglement in quantum network
cgtn.com
