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Updated: Nov 26, 2025

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Hyperentanglement concentration of nonlocal two-photon six-qubit systems via the cross-Kerr nonlinearity
Qian Liu1, Guo-Zhu Song2, Tian-Hui Qiu3
1Research Center for Quantum Optics and Quantum Communication, School of Science, Qingdao University of Technology, Qingdao, 266525, China. liuhan139@yeah.net.
Abstract:
We present an efficient hyperentanglement concentration protocol (hyper-ECP) for two-photon six-qubit systems in nonlocal partially hyperentangled Bell states with unknown parameters. In our scheme, we use two identical partially hyperentangled states which are simultaneously entangled in polarization and two different longitudinal momentum degrees of freedom (DOFs) to distill the maximally hyperentangled Bell state. The quantum nondemolition detectors based on the cross-Kerr nonlinearity are used to realize the parity checks of two-photon systems in three DOFs. The hyper-ECP can extract all the useful entanglement source, and the success probability can reach the theory limit with the help of iteration. All these advantages make our hyper-ECP useful in long-distance quantum communication in the future.
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