Eur. Phys. J. D 55, 235-242 (2009)
https://doi.org/10.1140/epjd/e2009-00237-y

Multipartite entanglement purification with quantum nondemolition detectors

¹ Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Beijing Normal University, Beijing, 100875, P.R. China
² College of Nuclear Science and Technology, Beijing Normal University, Beijing, 100875, P.R. China
³ Beijing Radiation Center, Beijing, 100875, P.R. China
⁴ Department of Physics, Applied Optics Beijing Area Major Laboratory, Beijing Normal University, Beijing, 100875, P.R. China

Corresponding author: ^a fgdeng@bnu.edu.cn

Received: 22 March 2009
Revised: 24 July 2009
Published online: 22 August 2009

Abstract

We present a scheme for multipartite entanglement purification of quantum systems in a Greenberger-Horne-Zeilinger state with quantum nondemolition detectors (QNDs). This scheme does not require the controlled-not gates which cannot be implemented perfectly with linear optical elements at present, but QNDs based on cross-Kerr nonlinearities. It works with two steps, i.e., the bit-flipping error correction and the phase-flipping error correction. These two steps can be iterated perfectly with parity checks and simple single-photon measurements. This scheme does not require the parties to possess sophisticated single photon detectors. These features maybe make this scheme more efficient and feasible than others in practical applications.