Entanglement swapping for Bell states and Greenberger-Horne-Zeilinger states in qubit systems

TL;DR

This paper introduces entanglement swapping techniques for Bell and GHZ states in qubit systems, providing formulas and schemes applicable to quantum communication protocols like key distribution and secret sharing.

Contribution

It presents new formulas and detailed schemes for entanglement swapping of Bell and GHZ states in multi-qubit systems, expanding quantum information processing capabilities.

Findings

Formulas for entanglement swapping in any number of qubits

Schemes for swapping multiple Bell and GHZ states

Applications in quantum key distribution and secret sharing

Abstract

We introduce a class of two-level multi-particle Greenberger-Horne-Zeilinger (GHZ) states, and study entanglement swapping between two systems for Bell states and the class of GHZ states in qubit systems, respectively. We give the formulas for the entanglement swapping of Bell states and GHZ states in any number of qubit systems. We further consider entanglement swapping between any number of Bell states and between any number of the introduced GHZ states, and propose a series of entanglement swapping schemes in a detailed way. 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.