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Entanglement is recognized as a key resource for quantum computation and quantum cryptography. For quantum metrology, the use of entangled states has been discussed and demonstrated as a means of improving the signal-to-noise ratio. In…

Quantum Physics · Physics 2007-05-23 C. F. Roos , M. Chwalla , K. Kim , M. Riebe , R. Blatt

Dicke states represent a class of multipartite entangled states that can be generated experimentally with many applications in quantum information. We propose a method to experimentally detect genuine multipartite entanglement in the…

Quantum Physics · Physics 2013-05-29 L. -M. Duan

The achievement of quantum supremacy boosted the need for a robust medium of quantum information. In this task, higher-dimensional qudits show remarkable noise tolerance and enhanced security for quantum key distribution applications.…

We transform the way of finding entanglement criterion into two steps: to obtain necessary criterion of separability by maximizing an algebra function for a set of characteristic variables of the witness operator and the given number of…

Quantum Physics · Physics 2016-05-30 Xiao-yu Chen , Zhu-an Xu

We establish a relation between concurrence and entanglement witnesses. In particular, we construct entanglement witnesses for three-qubit W and GHZ states in terms of concurrence and different set of operators that generate it. We also…

Quantum Physics · Physics 2008-06-05 Hoshang Heydari

A typical concept in quantum state analysis is based on the idea that states in the vicinity of some pure entangled state share the same properties; implying that states with a high fidelity must be entangled. States whose entanglement can…

Quantum Physics · Physics 2021-04-12 Otfried Gühne , Yuanyuan Mao , Xiao-Dong Yu

This short note describes a method to tackle the (bipartite) quantum separability problem. The method can be used for solving the separability problem in an experimental setting as well as in the purely mathematical setting. The idea is to…

Quantum Physics · Physics 2007-05-23 L. M. Ioannou , B. C. Travaglione

Quantum properties, such as entanglement and coherence, are indispensable resources in various quantum information processing tasks. However, there still lacks an efficient and scalable way to detecting these useful features, especially for…

Quantum Physics · Physics 2021-11-03 Yiwei Chen , Yu Pan , Guofeng Zhang , Shuming Cheng

Dicke states are a family of multi-qubit quantum states with interesting entanglement properties and have been observed in many experiments. We construct entanglement witnesses for detecting genuine multiparticle entanglement in the…

Quantum Physics · Physics 2013-09-13 Marcel Bergmann , Otfried Gühne

Suppose an experimentalist wishes to verify that his apparatus produces entangled quantum states. A finite amount of data cannot conclusively demonstrate entanglement, so drawing conclusions from real-world data requires statistical…

Quantum Physics · Physics 2010-10-22 Robin Blume-Kohout , Jun O. S. Yin , S. J. van Enk

Efficient certification and quantification of high dimensional entanglement of composite systems are challenging both theoretically as well as experimentally. Here, we demonstrate that several entanglement detection methods can be…

Quantum Physics · Physics 2026-01-28 Som Kanjilal , Vivek Pandey , Arun Kumar Pati

We establish a relation between entanglement of a many-body system and its diffractive properties, where the link is given by structure factors. Based on these, we provide a general analytical construction of multi-qubit entanglement…

We investigate bound entanglement in three-qubit mixed states which are diagonal in the Greenberger-Horne-Zeilinger (GHZ) basis. Entanglement in these states is detected using entanglement witnesses and the analysis focuses on states…

Quantum Physics · Physics 2024-11-05 Vaishali Gulati , Gayatri Singh , Kavita Dorai

Quantum entanglement is an essential resource for quantum technologies, and the controlled swap test provides a versatile tool for its detection and quantification. Here, we propose a SWAP-based entanglement witness that applies to…

Quantum Physics · Physics 2025-12-24 Sebastiano Guaraldo , Sonia Mazzucchi , Alessio Baldazzi , Stefano Azzini , Lorenzo Pavesi

It is well-known that the violation of a local uncertainty relation can be used as an indicator for the presence of entanglement. Unfortunately, the practical use of these non-linear witnesses has been limited to few special cases in the…

Entangled states are undoubtedly an integral part of various quantum information processing tasks. On the other hand, absolutely separable states which cannot be made entangled under any global unitary operations are useless from the…

Quantum Physics · Physics 2021-10-04 Ayan Patra , Shiladitya Mal , Aditi Sen De

We introduce a new entanglement measure based on optimal entanglement witness. First of all, we show that the entanglement measure satisfies some necessary properties, including zero entanglements for all separable states, convexity,…

Quantum Physics · Physics 2024-02-20 Nan Yang , Jiaji Wu , Xianyun Dong , Longyu Xiao , Jing Wang , Ming Li

The problem of determining whether a given quantum state is separable is known to be computationally difficult. We develop an approach to this problem based on approximations of convex polytopes in high dimensions. By showing that a convex…

Quantum Physics · Physics 2024-02-23 Samuel Dai , Ning Bao

Entanglement detection is essential in quantum information science and quantum many-body physics. It has been proved that entanglement exists almost surely for a random quantum state, while the realizations of effective entanglement…

Quantum Physics · Physics 2022-12-02 Pengyu Liu , Zhenhuan Liu , Shu Chen , Xiongfeng Ma

Coherence is a fundamental resource in quantum information processing, which can be certified by a coherence witness. Due to the imperfection of measurement devices, a conventional coherence witness may lead to fallacious results. We show…

Quantum Physics · Physics 2019-08-30 You-Qi Nie , Hongyi Zhou , Jian-Yu Guan , Qiang Zhang , Xiongfeng Ma , Jun Zhang , Jian-Wei Pan