Quantum analysis of teleportation quality degradation induced by loss and multiple-photon generation

In [R. A. Brewster, et al. Phys. Rev. A 104, 022411 (2021)], we considered the entanglement degradation due to multiple-photon-pair generation as measured by a Clauser-Horne-Shimony-Holt (CHSH) experiment. Here, we expound upon this technique to consider a quantum optical teleportation experiment that is subject to photon loss as well as input qubits and entangled states that potentially have more than a single photon per channel. We develop an elegant and generalized technique for computing the probability of success and fidelity of a quantum teleportation experiment that is agnostic to the photon statistics of the input state of the system.We then specify various example input states. This includes the ideal single-photon-per-channel case as well as a variety of cases where there are multiple photons per channel. In the multiphoton cases, we will let the qubit be generated using three different techniques and the entangled state be generated by type-II spontaneous parametric down conversion using two different techniques.We will also consider three different ways to perform the Bell state measurement optically in the quantum teleportation experiment. The single-photon-per-channel case agrees with what we can achieve analytically, allowing us to trust the results in the multiphoton cases.