Quantum entanglement creation for distant quantum memories via time-bin multiplexing

Quantum networks require parallel quantum entanglement between pairs of distant quantum memories (QMs) for practical applications. However, usually one pair of QMs is entangled using a single photonic pulse and multiple pulses are consumed to generate parallel entanglement between pairs of QMs. We propose a multiplexing method for simultaneously entangling multiple pairs of QMs located in two distant nodes. A single photon with high-dimensional encoding first entangles with all QMs in one node, leading to hybrid entanglement between a high-dimensional photon and two-dimensional QMs, and then it interacts with QMs in the other node and converts the hybrid entanglement to entanglement between multiple pairs of QMs in a heralded way. This can significantly increase the efficiency of large-scale quantum networks by reducing the exponential transmission loss via time-bin multiplexing. Furthermore, this protocol presents a specific connection between high-dimensional and two-dimensional quantum systems.