Related Experiment Video
Updated: May 18, 2026

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Quantifying tripartite entanglement of three-qubit generalized Werner states
Jens Siewert1, Christopher Eltschka
1Departamento de Química Física, Universidad del País Vasco UPV/EHU, 48080 Bilbao, Spain.
Abstract:
Multipartite entanglement is a key concept in quantum mechanics for which, despite the experimental progress in entangling three or more quantum devices, there is still no general quantitative theory that exists. In order to characterize the robustness of multipartite entanglement, one often employs generalized Werner states, that is, mixtures of a Greenberger-Horne-Zeilinger (GHZ) state and the completely unpolarized state. While two-qubit Werner states have been instrumental for various important advancements in quantum information, as of now there is no quantitative account for such states of more than two qubits. By using the GHZ symmetry introduced recently, we find exact results for tripartite entanglement in three-qubit generalized Werner states and, moreover, the entire family of full-rank mixed states that share the same symmetries.
Related Concept Videos
The Entropy as a State Function
Spin–Spin Coupling: Three-Bond Coupling (Vicinal Coupling)
The extent of coupling depends on the C‑C bond length, the two H‑C‑C angles, any electron-withdrawing substituents, and the dihedral angle between the involved orbitals. The...
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule
The Uncertainty Principle
Atomic Nuclei: Nuclear Spin State Overview
Absolute Entropies and the Third Law of Thermodynamics