Activation of metrologically useful genuine multipartite entanglement

Trényi, Róbert; Lukács, Árpád; Horodecki, Paweł; Horodecki, Ryszard; Vértesi, Tamás; Tóth, Géza

Abstract

We consider quantum metrology with several copies of bipartite and multipartite quantum states. We characterize the metrological usefulness by determining how much the state outperforms separable states. We identify a large class of entangled states that become maximally useful for metrology in the limit of large number of copies, even if the state is weakly entangled and not even more useful than separable states. This way we activate metrologically useful genuine multipartite entanglement. Remarkably, not only that the maximally achievable metrological usefulness is attained exponentially fast in the number of copies, but it can be achieved by the measurement of few simple correlation observables. We also make general statements about the usefulness of a single copy of pure entangled states. We surprisingly find that the multiqubit states presented in Hyllus et al (2010 Phys. Rev. A 82 012337), which are not useful, become useful if we embed the qubits locally in qutrits. We discuss the relation of our scheme to error correction, and its possible use for quantum metrology in a noisy environment.

Citation

Trényi, R., Lukács, Á., Horodecki, P., Horodecki, R., Vértesi, T., & Tóth, G. (2024). Activation of metrologically useful genuine multipartite entanglement. New Journal of Physics, 26(2), Article 023034. https://doi.org/10.1088/1367-2630/ad1e93

• Journal Article Type: Article
• Acceptance Date: Jan 15, 2024
• Online Publication Date: Feb 16, 2024
• Publication Date: Feb 16, 2024
• Deposit Date: Mar 18, 2024
• Publicly Available Date: Mar 18, 2024
• Journal: New Journal of Physics
• Electronic ISSN: 1367-2630
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 26
• Issue: 2
• Article Number: 023034
• DOI: https://doi.org/10.1088/1367-2630/ad1e93
• Keywords: quantum metrology, quantum entanglement, genuine multipartite entanglement
• Public URL: https://durham-repository.worktribe.com/output/2258036