An entanglement concentration protocol for cluster states

Binayak Samadder Choudhury, Arpan Dhara

Mitali Sisodia, Chitra Shukla, Gui‐Lu Long

Sheng-Yang Zhao, Jiong Liu, Lan Zhou +1 more

Bin Si, Shi‐Lei Su, Li-Li Sun +3 more

We propose an entanglement concentration protocol to concentrate an arbitrary partially-entangled four-photon cluster state. As a pioneering three-step entanglement concentration scheme, our protocol only needs a single-photon resource to assist the concentration in each step, which makes this protocol more economical. With the help of the linear optical elements and weak cross-Kerr nonlinearity, one can obtain a maximally-entangled cluster state via local operations and classical communication. Moreover, the protocol can be iterated to obtain a higher success probability and is feasible under current experimental conditions.

Lan Zhou

We present a highly efficient entanglement concentration protocol (ECP) for a four-electron system in a less-entangled cluster state. In this ECP, we only require one pair of less-entangled electron cluster states and one ancillary electron to complete the task. With the help of the controlled-not (CNOT) gate, the concentrated maximally entangled state can be retained for further application with some success probability. On the other hand, the discarded items can be reused to obtain a high success probability. All the features make this ECP useful in the current quantum information field.

Binayak Samadder Choudhury, Arpan Dhara