Two-step hyperentanglement purification with the quantum-state-joining method

TL;DR

This paper introduces a two-step hyperentanglement purification protocol utilizing the quantum-state-joining method, enhancing efficiency and fidelity in long-distance quantum communication by effectively correcting polarization and spatial-mode errors.

Contribution

It presents a novel two-step purification protocol that leverages QSJM to improve efficiency and fidelity in hyperentanglement purification over previous methods.

Findings

High purification efficiency achieved.

Effective correction of polarization and spatial-mode errors.

Improved entanglement fidelity for long-distance communication.

Abstract

Hyperentanglement is a promising resource in quantum information processing, especially for increasing the channel capacity of long-distance quantum communication. Hyperentanglement purification is an important method to obtain high-fidelity nonlocal hyperentangled states from mixed hyperentangled states in a long-distance quantum communication process with noisy channels. Here, we present a two-step hyperentanglement purification protocol for nonlocal mixed hyperentangled states with polarization bit-flip errors and spatial-mode phase-flip errors, resorting to polarization-spatial phase-check quantum nondemolition detectors and the quantum-state-joining method (QSJM). With QSJM, the protocol can preserve the states that are discarded in the previous hyperentanglement purification protocols. It has the advantage of a high efficiency, and it is useful for improving the entanglement of photon systems with several degrees of freedom in long-distance high-capacity quantum communication.