Quantum Repeater and System and Method for Creating Extended Entanglements

摘要

A quantum repeater (80) performs quantum local link entanglements (LLE) with left and right neighbour nodes to produce entangled photon pairs, under the control of left- and right-side control units (82,83) . A merge control unit (87) then carries out entanglement swapping at the repeater using photons from each pair, so that photons in the left and right neighbour nodes become entangled. This procedure may be carried out iteratively using a chain of repeaters to transfer entanglements large distances (e.g. fig.9, not shown). Prior to a merge operation, a repeater waits to receive notification from its preceding neighbour indicating that the neighbour has successfully merged its pairs, and the repeater also ensures that an entangled pair exists between it and the succeeding neighbour. Applications include quantum key distribution (QKD) and quantum computing.