Experimental nonlocality-based network diagnostics of multipartite entangled states

Area of Science:

• Quantum Information Science
• Quantum Optics
• Quantum Computing

Background:

• Multipartite entangled states are crucial for quantum information processing.
• Assessing the quality of entangled states and the gates used to create them is essential for reliable quantum technologies.
• Current diagnostic methods may not be sufficient for complex multipartite networks.

Purpose of the Study:

• To introduce a novel diagnostic scheme for multipartite networks of entangled particles.
• To assess the quality of quantum gates used in the engineering of entangled states.
• To establish conditions bounding the quality of entangled bonds within a quantum register.

Main Methods:

• Utilizing a set of carefully selected multiparticle Bell tests.
• Gathering information from these tests to derive bounding conditions for entanglement quality.
• Applying the diagnostic scheme to a hybrid quantum resource combining two-photon hyperentanglement and photonic-chip technology.

Main Results:

• Successfully identified conditions that bound the quality of entangled bonds in multipartite networks.
• Demonstrated the effectiveness of the proposed diagnostic scheme through characterization of a specific quantum resource.
• Validated the scheme's applicability to a system integrating hyperentanglement and photonic integrated circuits.

Conclusions:

• The developed diagnostic scheme provides a robust method for assessing quantum entanglement quality in multipartite networks.
• The approach is suitable for analyzing modular quantum resources, such as cluster states.
• Opens avenues for section-by-section analysis of larger photonic quantum systems and future studies on medium-sized networks.