Entanglement Verification of Hyperentangled Photon Pairs

TL;DR

This paper experimentally investigates hyperentangled photon pairs, demonstrating their higher-dimensional entanglement and steerability, and showing that advanced Bell tests can reveal their complex quantum nature in a device-independent manner.

Contribution

It provides the first experimental verification of higher-dimensional entanglement and steerability in hyperentangled states using advanced Bell inequalities.

Findings

Hyperentangled states exhibit higher-dimensional entanglement.

Bell tests beyond CHSH reveal the higher-dimensional nature.

Hyperentangled states are steerable across multiple degrees of freedom.

Abstract

We experimentally investigate the properties of hyperentangled states displaying simultaneous entanglement in multiple degrees of freedom, and find that Bell tests beyond the standard Clauser, Horne, Shimony, Holt inequality can reveal a higher-dimensional nature in a device-independent way. Specifically, we show that hyperentangled states possess more than just simultaneous entanglement in separate degrees of freedom but also entanglement in a higher dimensional Hilbert space. We also verify the steerability of hyperentangled quantum states by steering different photonic degrees of freedom.