Entanglement Swapping of Generalized GHZ States

Zhaoxu Ji, Peiru Fan, Huanguo Zhang

We introduce a class of multi-particle Greenberger-Horne-Zeilinger (GHZ) states, and study entanglement swapping between two qubit systems for Bell states and for the class of GHZ states, respectively. We generalize the bi-system entanglement swapping of Bell states and multi-particle GHZ states to any number of qubit systems. We further study the entanglement swapping schemes between any number of Bell states and between any number of the introduced GHZ states in a detailed way, and propose the schemes that can generate two identical GHZ states. We illustrate the applications of such schemes in quantum information processing by proposing quantum protocols for quantum key distribution, quantum secret sharing and quantum private comparison.

홍정식

Chia‐Wei Tsai, Tzonelih Hwang

This study uses the Greenberger–Horne–Zeilinger (GHZ)-like state to establish an entanglement swapping protocol on a pure GHZ state. A quantum circuit is proposed to assist in teleporting the entanglement of the pure GHZ state. Furthermore, on the basis of the generation of the GHZ-like state, an improved protocol to reduce the number of transmitted photons required in the process of entanglement swapping is proposed.

Binayak Samadder Choudhury, Arpan Dhara

Zhong‐Xiao Man, Yun‐Jie Xia, Nguyen Ba An

We present a three-party quantum secure direct communication protocol by using Greenberg–Horne–Zeilinger (GHZ) states and entanglement swapping. The proposed scheme realizes authorized parties' secure exchange of their respective secret messages simultaneously and directly in a set of devices. We show that the scheme is secure against eavesdropper's commonly used attacks. We also generalize the protocol to the N -party case by using N -partite GHZ states.

Anthony Short, Sandu Popescu, Nicolas Gisin