  Recent advances in quantum technologies are rapidly stimulating the building
of quantum networks. With the parallel development of multiple physical
platforms and different types of encodings, a challenge for present and future
networks is to uphold a heterogeneous structure for full functionality and
therefore support modular systems that are not necessarily compatible with one
another. Central to this endeavor is the capability to distribute and
interconnect optical entangled states relying on different discrete and
continuous quantum variables. Here we report an entanglement swapping protocol
connecting such entangled states. We generate single-photon entanglement and
hybrid entanglement between particle-like and wave-like optical qubits, and
then demonstrate the heralded creation of hybrid entanglement at a distance by
using a specific Bell-state measurement. This ability opens up the prospect of
connecting heterogeneous nodes of a network, with the promise of increased
integration and novel functionalities.
