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We present methods for detecting entanglement around symmetric Dicke states. In particular, we consider N-qubit symmetric Dicke states with N/2 excitations. In the first part of the paper we show that for large N these states have the…

Quantum Physics · Physics 2007-05-23 Geza Toth

Entanglement is a ubiquitous feature of low temperature systems and believed to be highly relevant for the dynamics of condensed matter properties and quantum computation even at higher temperatures. The experimental certification of this…

Quantum Physics · Physics 2016-01-07 Stefan Bäuml , Dagmar Bruß , Marcus Huber , Hermann Kampermann , Andreas Winter

We utilize Kolmogorov-Arnold Networks to design an interpretable model capable of detecting quantum entanglement within a set of nine-parameter two-qubit states. This network serves as an entanglement witness, achieving an accuracy of…

Quantum Physics · Physics 2025-12-09 Fatemeh Lajevardi , Azam Mani , Ali Fahim

From a practical perspective it is advantageous to develop methods that verify entanglement in quantum states with as few measurements as possible. In this paper we investigate the minimal number of mutually unbiased bases (MUBs) needed to…

Quantum Physics · Physics 2023-03-14 Joonwoo Bae , Anindita Bera , Dariusz Chruściński , Beatrix C. Hiesmayr , Daniel McNulty

We address the problem of optimising entanglement witnesses when a limited fixed set of local measurements can be performed on a bipartite system, thus providing a procedure, feasible also for experiments, to detect entangled states using…

Quantum Physics · Physics 2020-07-01 Alberto Riccardi , Dariusz Chruściński , Chiara Macchiavello

Entanglement is assuming a central role in modern quantum many-body physics. Yet, for lattice gauge theories its certification remains extremely challenging. A key difficulty stems from the local gauge constraints underlying the gauge…

High Energy Physics - Theory · Physics 2022-09-26 Veronica Panizza , Ricardo Costa de Almeida , Philipp Hauke

From the physical point of view entanglement witnesses define a universal tool for analysis and classification of quantum entangled states. From the mathematical point of view they provide highly nontrivial generalization of positive…

Quantum Physics · Physics 2014-12-30 Dariusz Chruściński , Gniewomir Sarbicki

Entanglement is a key property of quantum states that acts as a resource for a wide range of tasks in quantum computing. Entanglement detection is a key conceptual and practical challenge. Without adaptive or joint measurements,…

Quantum Physics · Physics 2026-04-07 K. Bharati , Vikesh Siddhu , Krishna Jagannathan

A generic model of measurement device which is able to directly measure commonly used quantum-state characteristics such as fidelity, overlap, purity and Hilbert-Schmidt distance for two general uncorrelated mixed states is proposed. In…

Quantum Physics · Physics 2009-11-07 Radim Filip

A new criterium to detect the entanglement present in a {\it hyperentangled state}, based on the evaluation of an entanglement witness, is presented. We show how some witnesses recently introduced for graph states, measured by only two…

Quantum Physics · Physics 2008-12-05 Giuseppe Vallone , Raino Ceccarelli , Francesco De Martini , Paolo Mataloni

The question under what conditions different witnesses may detect some entangled states simultaneously is answered for both finite- and infinite-dimensional bipartite systems. Finite many different witnesses can detect some entangled states…

Mathematical Physics · Physics 2011-07-05 Jinchuan Hou , Yu Guo

The future of quantum communication relies on quantum networks composed by observers sharing multipartite quantum states. The certification of multipartite entanglement will be crucial to the usefulness of these networks. In many real…

Quantum Physics · Physics 2016-02-16 D. Cavalcanti , P. Skrzypczyk , G. H. Aguilar , R. V. Nery , P. H. Souto Ribeiro , S. P. Walborn

An entanglement witness is an observable with the property that a negative expectation value signals the presence of entanglement. The question arises how a witness can be improved if the expectation value of a second observable is known,…

Quantum Physics · Physics 2018-08-03 Mariami Gachechiladze , Nikolai Wyderka , Otfried Gühne

An entanglement witness (EW) is an operator that allows to detect entangled states. We give necessary and sufficient conditions for such operators to be optimal, i.e. to detect entangled states in an optimal way. We show how to optimize…

Quantum Physics · Physics 2009-11-06 M. Lewenstein , B. Kraus , J. I. Cirac , P. Horodecki

Quantum phenomena such as entanglement provide powerful resources for enhancing classical sensing. Here, we theoretically show that collective entanglement of spin qubits, arising from a condensation of particle-hole pairs, can strongly…

Characterizing entanglement in quantum materials is crucial for advancing next-generation quantum technologies. Despite recent strides in witnessing entanglement in magnetic materials with distinguishable spin modes, quantifying…

Strongly Correlated Electrons · Physics 2025-03-27 Tongtong Liu , Luogen Xu , Jiarui Liu , Yao Wang

We construct three-qubit entanglement witnesses with relatively simple structures. Despite their simplicity, these witnesses are capable of detecting a number of bound entangled states more effectively. To illustrate this, two families of…

Quantum Physics · Physics 2017-06-13 Yahya Akbari-Kourbolagh

Quantum networks form the backbone of long-distance quantum information processing. Genuine multipartite entanglement (GME) serves as a key indicator of network performance and overall state quality. However, the widely used methods for…

Quantum Physics · Physics 2026-01-13 Jing-Tao Qiu , D. M. Tong , Xiao-Dong Yu

Detecting genuine multipartite entanglement (GME) is a state-characterization task that benchmarks coherence and experimental control in quantum systems. Existing GME tests often require joint measurements on many qubits, posing challenges…

Quantum Physics · Physics 2026-02-18 Nicky Kai Hong Li , Xi Dai , Manuel H. Muñoz-Arias , Kevin Reuer , Marcus Huber , Nicolai Friis

Mutually unbiased bases (MUBs) provide a standard tool in the verification of quantum states, especially when harnessing a complete set for optimal quantum state tomography. In this work, we investigate the detection of entanglement via…

Quantum Physics · Physics 2021-09-14 B. C. Hiesmayr , D. McNulty , S. Baek , S. Singha Roy , J. Bae , D. Chruściński