Frequency-insensitive spatiotemporal shaping of single photon in multiuser quantum network

Abstract

Exploiting the fundamental features of quantum mechanics, an entanglement-based quantum network offers a promising platform for many dramatic applications such as multi-user cryptography. Nevertheless, the implementation of a large-scale quantum network in real-world scenarios remains challenging owing to the multiple scattering events in complex environment, particularly those frequency-sensitive scatterings that disturb quantum correlation both spatially and temporally. Here, we demonstrate the frequency-insensitive spatiotemporal control of entangled photons in a fully connected network by leveraging a Fourier-transform setup and the genetic algorithm. Such an approach can effectively improve the entanglement distribution process through a multimode fiber while the quantum characteristic of the network can be maintained well after the spatiotemporal shaping. Our scheme can serve as a bridging technology to establish entanglement between remote nodes of spectrally interconnected quantum systems and has great potential applications in future real-world quantum networks.