# Economical multi-photon polarization entanglement purification with Bell state

Authors
• 1 Nanjing University of Posts and Telecommunications, Nanjing, 210003, China , Nanjing (China)
Type
Published Article
Journal
Quantum Information Processing
Publisher
Springer-Verlag
Publication Date
Aug 03, 2021
Volume
20
Issue
8
Identifiers
DOI: 10.1007/s11128-021-03192-z
Source
Springer Nature
Keywords
Disciplines
• Article
We present an economical entanglement purification protocol for the multi-photon polarization-entangled system in a Greenberger–Horne–Zeilinger (GHZ) state. We use one pair of two-photon Bell state or M-photon GHZ state (M<N\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$M<N$$\end{document}) to correct the error in the polarization entanglement of an N-photon system. This protocol only uses linear optical elements, so that it is feasible in current experiment. The parties can obtain a high-quality entangled polarization state from each less-entangled N-photon system, by consuming only the Bell state, or the M-photon GHZ state. It is far different from conventional multipartite entanglement purification protocols. It also requires less local operation and classical communication than other purification protocols. Our protocol especially suits for the case where we can precisely know which channel or channels are more noisy. This protocol may be useful in current and future long-distance quantum communication.