Entanglement and teleportation between polarization and wave-like encodings of an optical qubit

Light is an irreplaceable means of communication among various quantum information processing and storage devices. Due to their different physical nature, some of these devices couple more strongly to discrete, and some to continuous degrees of freedom of a quantum optical wave. It is therefore desirable to develop a technological capability to interconvert quantum information encoded in these degrees of freedom. Here we generate and characterize an entangled state between a dual-rail (polarization-encoded) single-photon qubit and a qubit encoded as a superposition of opposite-amplitude coherent states. We furthermore demonstrate the application of this state as a resource for the interfacing of quantum information between these encodings. In particular, we show teleportation of a polarization qubit onto a freely propagating continuous-variable qubit. Interfacing quantum information between discrete and continuous would allow exploiting the best of both worlds, but it has been shown only for single-rail encoding. Here, the authors extend this to the more practical dual-rail encoding, realizing teleportation between a polarization qubit and a CV qubit.