Entangling remote qubits using the single-photon protocol: an in-depth theoretical and experimental study

A future quantum internet will allow for unprecedented applications like fundamentally secure communication, distributed quantum computation and enhancing the sensitivity of quantum sensors. The envisioned quantum internet will consist of several nodes, connected via quantum entanglement.



To generate the entangled links between distant nodes, one can use several protocols which all rely on the transfer of photons between the nodes. The single-photon entanglement scheme, initially proposed by Cabrillo et. al. and Bose et. al. in 1999, is especially suited for achieving entangled states with high generation rates in the presence of high photon loss and has been implemented on various qubit platforms. Towards high quality entangled links, we need to understand how different noise and error sources affect the entangled states.



In this talk, I will present a detailed theoretical and experimental study of the single-photon entanglement protocol. We consider the effect of various noise and error sources, such as the inherent protocol error, distinguishability of the photons, and two-photon emission events. These imperfections are general of nature and are not specific to our qubit platform. Therefore, the insights gained in this work are applicable to many other qubit systems.



[1] S. L. N. Hermans et al., “Entangling remote qubits using the single-photon protocol: an in-depth theoretical and experimental study.” doi: 10.48550/arXiv.2208.07449.