Entanglement Swapping via Collective Decay

Anjali N. Nair, R. Arun

Ting Yu

Yueh-Nan Chen, Shin-Liang Chen, Neill Lambert +3 more

We propose a scheme to realize entanglement swapping via superradiance, entangling two distant cavities without a direct interaction. The successful Bell-state-measurement outcomes are performed naturally by the electromagnetic reservoir, and we show how, using a quantum trajectory method, the nonlocal properties of the state obtained after the swapping procedure can be verified by the steering inequality. Furthermore, we discuss how the unsuccessful measurement outcomes can be used in an experiment of delayed-choice entanglement swapping. An extension of testing the quantum steering inequality with the observers at three different times is also considered.

Zhi He, Chao‐Yun Long, Shuijie Qin +1 more

We proposed a scheme to implement the entanglement swapping based on cavity QED. Using this scheme, we can obtain the entanglement swapping with the success probability of 100% for a two atoms system and a three atoms system respectively, and the entanglement swapping is insensitive to both the cavity decay and thermal field.

Anthony Chefles, Claire R Gilson, Stephen M Barnett

Vojtěch Trávníček, Karol Bartkiewicz, Antonín Černoch +1 more

This paper reports on the experimental diagnostics of an entanglement-swapping protocol by means of collective entanglement witness. Our approach is suitable to detect disturbances occurring in the preparation of quantum states, quantum-communication channels, and imperfect Bell-state projections. More specifically, we demonstrate that our method can distinguish disturbances such as depolarization, phase damping, amplitude damping, and imperfect Bell-state measurement by observing four probabilities and estimating collective entanglement witness. Since entanglement swapping is a key procedure for quantum repeaters, quantum relays, device-independent quantum communications, and entanglement-assisted error correction, this can aid in faster and practical resolutions of quality of transmission related problems as our approach requires fewer measurements than other means of diagnostics.