Roman Goncharov

We analyze the performance of a quantum repeater scheme that uses multimode Schrödinger cat states. In this scheme, the entanglement generation and swapping protocols utilize entangled cat states produced using electro-optic modulation of single-mode optical cats. In our analysis, we adapt the approach of doubling the number of links that reduces complexity of constructing the final network and simplifies analytical treatment. In order to evaluate the mean waiting time, we employ both the mean-only approximation and exact results and determine the values of the success probabilities of entanglement generation and swapping at which the approximate results are close to the exact ones. Distance dependence of the repeater rate is calculated depending on the number of elementary links. The results are used to perform a comparative analysis of quantum repeater schemes using the modulated cat states and the photon-pair states generated via spontaneous parametric down-conversion. It is shown that the use of the cat states provides several advantages over the photon pairs. Entanglement purification protocols for optical cats are discussed.