Hyperconcentration for multipartite entanglement via linear optics

TL;DR

This paper proposes a linear optics-based hyperconcentration scheme to convert partially hyperentangled N-photon GHZ states into maximally hyperentangled states, enhancing quantum communication capabilities.

Contribution

It introduces a practical hyperconcentration protocol for multipartite hyperentangled states using only linear optical elements, suitable for current technology.

Findings

Achieves maximally hyperentangled states with certain probability

Uses only linear optical elements, making it feasible

Applicable to N-photon GHZ states in polarization and spatial modes

Abstract

We present a hyperconcentration scheme for nonlocal $N$-photon hyperentangled Greenberger-Horne-Zeilinger states. The maximally hyperentangled state, in which $N$ particles are entangled simultaneously in the polarization and the spatial mode, can be obtained with a certain probability from two partially hyperentangled states. The hyperconcentration scheme is based on one polarization parity check measurement, one spatial mode parity check measurement and N-2 single-photon two-qubit measurements. The concentration only requires linear optical elements, which makes it feasible and practical with current technology.