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Related papers: Quantifying entanglement with covariance matrices

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The detection of entanglement in a bipartite state is a crucial issue in quantum information science. Based on realignment of density matrices and the vectorization of the reduced density matrices, we introduce a new set of separability…

Quantum Physics · Physics 2024-12-09 Yu Lu , Zhong-Xi Shen , Shao-Ming Fei , Zhi-Xi Wang

Entanglement, and quantum correlation, are precious resources for quantum technologies implementation based on quantum information science, such as, for instance, quantum communication, quantum computing, and quantum interferometry.…

Quantum Physics · Physics 2023-05-22 Arthur Vesperini , Ghofrane Bel-Hadj-Aissa , Roberto Franzosi

This review focuses on the field of quantum entanglement applied to condensed matter physics systems with strong correlations, a domain which has rapidly grown over the last decade. By tracing out part of the degrees of freedom of…

Strongly Correlated Electrons · Physics 2016-08-11 Nicolas Laflorencie

Measuring entanglement is a demanding task that usually requires full tomography of a quantum system, involving a number of observables that grows exponentially with the number of parties. Recently, it was suggested that adding a single…

We present here an overview of our work concerning entanglement properties of composite quantum systems. The characterization of entanglement, i.e. the possibility to assert if a given quantum state is entangled with others and how much…

Quantum Physics · Physics 2007-05-23 K. Eckert , O. Gühne , F. Hulpke , P. Hyllus , J. Korbicz , J. Mompart , D. Bruß , M. Lewenstein , A. Sanpera

Uncertainty principle is an inherent nature of quantum system that undermines the precise measurement of incompatible observables and hence the applications of quantum theory. Entanglement, another unique feature of quantum physics, was…

Quantum Physics · Physics 2020-09-30 Jun-Li Li , Cong-Feng Qiao

We explore the possibility of entanglement detection in continuous variable systems by entanglement witnesses based on covariance matrices, constructible from random homodyne measurements. We propose new linear constraints characterizing…

Quantum Physics · Physics 2021-01-20 Tatiana Mihaescu , Hermann Kampermann , Giulio Gianfelici , Aurelian Isar , Dagmar Bruss

In this paper we study the reduction criterion for detecting entanglement of large dimensional bipartite quantum systems. We first obtain an explicit formula for the moments of a random quantum state to which the reduction criterion has…

Mathematical Physics · Physics 2014-12-02 Maria Anastasia Jivulescu , Nicolae Lupa , Ion Nechita

We study the entanglement of a multipartite quantum state. An inequality between the bipartite concurrence and the multipartite concurrence is obtained. More effective lower and upper bounds of the multipartite concurrence are obtained. By…

Quantum Physics · Physics 2015-05-19 Ming Li , Shao-Ming Fei , Zhi-Xi Wang

While commonly used entanglement criteria for continuous variable systems are based on quadrature measurements, here we study entanglement detection from measurements of the Wigner function. These are routinely performed in platforms such…

Quantum Physics · Physics 2026-03-25 Shuheng Liu , Jiajie Guo , Qiongyi He , Matteo Fadel

Criteria of measure quantifying quantum coherence, a unique property of quantum system, are proposed recently. In this paper, we first give an uncertainty-like expression relating the coherence and the entropy of quantum system. This…

Quantum Physics · Physics 2015-07-15 Zhengjun Xi , Yongming Li , Heng Fan

Multipartite entanglement is the premier resource for quantum technologies. Yet, its exact quantification in the laboratory is notoriously challenging, typically requiring the full knowledge of high dimensional quantum states. Here, we…

Quantum Physics · Physics 2026-05-05 Francois Payn , Davide Girolami

The quantum mechanics formalism introduced new revolutionary concepts challenging our everyday perceptions. Arguably, quantum entanglement, which explains correlations that cannot be reproduced classically, is the most notable of them.…

We derive an analytical expression for the lower bound of the concurrence of mixed quantum states of composite 2xK systems. In contrast to other, implicitly defined entanglement measures, the numerical evaluation of our bound is…

Quantum Physics · Physics 2009-11-10 Artur Lozinski , Andreas Buchleitner , Karol Zyczkowski , Thomas Wellens

In recent years considerable progress has been made towards developing a general theory of quantum entanglement. In particular, criteria to decide whether a given quantum state is entangled are of high theoretical and practical interest.…

Quantum Physics · Physics 2025-01-27 Shruti Aggarwal

We present a theoretical study of the relationship between entanglement and entropy in multi-qubit quantum optical systems. Specifically we investigate quantitative relations between the concurrence and linear entropy for a two-qubit mixed…

Quantum Physics · Physics 2009-11-10 Alexandra Olaya-Castro , Neil F. Johnson , Luis Quiroga

The concurrence, a quantitative measure of the entanglement between a pair of particles, is determined for the case where the pair is extracted from a symmetric state of N two-level systems. Examples are given for both pure and mixed states…

Quantum Physics · Physics 2009-11-07 Xiaoguang Wang , Klaus Molmer

We review and generalize the recently introduced framework of entropy vectors for detecting and quantifying genuine multipartite entanglement in high dimensional multicomponent quantum systems. We show that these ideas can be extended to…

Quantum Physics · Physics 2013-10-22 Marcus Huber , Martí Perarnau-Llobet , Julio I. de Vicente

Entanglement is not only the resource that fuels many quantum technologies but also plays a key role for some of the most profound open questions of fundamental physics. Experiments controlling quantum systems at the single quantum level…

Quantum Physics · Physics 2021-06-02 Bjarne Bergh , Martin Gärttner

We study emerging notions of quantum correlations in compound systems. Based on different definitions of quantumness in individual subsystems, we investigate how they extend to the joint description of a composite system. Especially, we…

Quantum Physics · Physics 2017-06-12 J. Sperling , E. Agudelo , I. A. Walmsley , W. Vogel