2021/11/25 by Ming-Xing Luo, Ming‐Xing Luo, Shao-Ming Fei +5
Computer Science · Physics and Astronomy · #Bipartite graph #Cluster state #Computer science #Density matrix #Entanglement witness #FOS: Physical sciences #Graph #Greenberger–Horne–Zeilinger state #Hilbert space #Multipartite #Multipartite entanglement #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum Physics (quant-ph) #Quantum channel #Quantum computer #Quantum entanglement #Quantum information #Quantum mechanics #Quantum state #Quantum tomography #Robustness (evolution) #Squashed entanglement #Theoretical computer science #W state #quant-ph
paper · pdf · doi:10.48550/arxiv.2111.12902
published in arXiv (Cornell University) (Cornell University) · 5+9 pages, 4 figures
arxiv created 2021/11/25 · openalex publication_date 2021/11/25 · arxiv updated 2021/11/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Quantum entangled states have shown distinguished features beyond any classical state. Many methods like quantum state tomography have been presented to verify entanglement. In this work, we aim to identify unknown entanglements with partial information of the state space by developing a nonlinear entanglement witness. The witness consists of a generalized Greenberger-Horne-Zeilinger-like paradox expressed by Pauli observables, and a nonlinear inequality expressed by density matrix elements. First, we verify unknown bipartite entanglements and study the robustness of entanglement witnesses against the white noise. Second, we generalize such a verification to unknown multipartite entangled states, including the Greenberger-Horne-Zeilinger-type states and the cluster states under local channel operations. Third, we give a quantum-information application related to the quantum zero-knowledge proof. Our results provide a useful method in verifying universal quantum computation resources with robustness against white noises. Our work is applicable to detect unknown entanglement without the state tomography.