Analytical model for real-world experiments in quantum teleportation

Arguably all experiments in quantum information science resort to using non-ideal quantum states to perform a task. Here we apply phase space methods to model experiments that use weak coherent states as well as two-mode squeezed vacuum states—non-ideal states regularly used in quantum communication and networks-- to approximate ideal single photon and two-photon entangled states respectively. Specifically, we develop an analytical model for quantum teleportation of time-bin qubits based on an approach used at the Caltech and Fermilab Quantum Networks. Our model is based on a characteristic function approach and includes all experimentally relevant parameters, such as channel loss, photon distinguishability, detector dark counts, and contributions from the multi-photon events. Comparing the outcomes of our simulations with experimental results allowed us to unambiguously and quantitatively determine the limiting factors behind the fidelity of quantum teleportation, namely photon distinguishability in the aforementioned experiments.