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Related papers: Entanglement degree for Jaynes-Cummings model

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We present a concise introduction to quantum entanglement. Concentrating on bipartite systems we review the separability criteria and measures of entanglement. We focus our attention on geometry of the sets of separable and maximally…

Quantum Physics · Physics 2007-05-23 Karol Zyczkowski , Ingemar Bengtsson

Entanglement of formation for a class of higher dimensional quantum mixed states is studied in terms of a generalized formula of concurrence for $N$-dimensional quantum systems. As applications, the entanglement of formation for a class of…

Quantum Physics · Physics 2009-11-10 Shao-Ming Fei , Juergen Jost , Xianqing Li-Jost , Guo-Fang Wang

This paper gives a criterion for detecting the entanglement of a quantum state, and uses it to study the relationship between topological and quantum entanglement. It is fundamental to view topological entanglements such as braids as…

Quantum Physics · Physics 2009-11-10 Louis H. Kauffman , Samuel J. Lomonaco

Entanglement is a fundamental aspect of quantum physics, both conceptually and for its many applications. Classifying an arbitrary multipartite state as entangled or separable -- a task referred to as the separability problem -- poses a…

We report the creation of a wide range of quantum states with controllable degrees of entanglement and entropy using an optical two-qubit source based on spontaneous parametric downconversion. The states are characterised using measures of…

Quantum Physics · Physics 2009-11-07 A. G. White , D. F. V. James , W. J. Munro , P. G. Kwiat

A critical requirement for diverse applications in Quantum Information Science is the capability to disseminate quantum resources over complex quantum networks. For example, the coherent distribution of entangled quantum states together…

Quantum Physics · Physics 2009-11-11 C. W. Chou , H. de Riedmatten , D. Felinto , S. V. Polyakov , S. J. van Enk , H. J. Kimble

Maximally entangled mixed states are those states that, for a given mixedness, achieve the greatest possible entanglement. For two-qubit systems and for various combinations of entanglement and mixedness measures, the form of the…

Entanglement serves as a fundamental resource for various quantum information processing tasks. Fidelity of entanglement (which measures the proximity to a maximally entangled state) and various quantum entropies are key indicators for…

Quantum Physics · Physics 2025-10-21 Komal Kumar , Bivas Mallick , Tapaswini Patro , Nirman Ganguly

This article studies quantum mechanical entanglement. We begin by illustrating why entanglement implies action at a distance. We then introduce a simple criterion for determining when a pure quantum state is entangled. Finally, we present a…

Quantum Physics · Physics 2022-09-01 Stan Gudder

The entanglement quantification and classification of multipartite quantum states are two important research fields in quantum information. In this work, we study the entanglement of arbitrary-dimensional multipartite pure states by looking…

Quantum Physics · Physics 2013-06-18 Hui Li , Shuhao Wang , Jianlian Cui , Gui-Lu Long

Quantum entanglement, as one of the fundamental concepts in quantum mechanics, has garnered significant attention over the past few decades for its extraordinary nonlocality. With the advancement of quantum technology, quantum entanglement…

Quantum Physics · Physics 2025-11-27 Chi Zhang

Quantum entanglement is a fundamental property commonly used in various quantum information protocols and algorithms. Nonetheless, the problem of identifying entanglement has still not reached a general solution for systems larger than…

Quantum Physics · Physics 2024-08-20 Jarosław Pawłowski , Mateusz Krawczyk

Entanglement properties are routinely used to characterize phases of quantum matter in theoretical computations. For example the spectrum of the reduced density matrix, or so-called "entanglement spectrum", has become a widely used…

Mesoscale and Nanoscale Physics · Physics 2018-08-29 Kenny Choo , Curt W. von Keyserlingk , Nicolas Regnault , Titus Neupert

Measurements in the quantum domain can exceed classical notions. This concerns fundamental questions about the nature of the measurement process itself, as well as applications, such as their function as building blocks of quantum…

Quantum Physics · Physics 2023-02-02 Jan Sperling , Ilaria Gianani , Marco Barbieri , Elizabeth Agudelo

We study the correlations of classical and quantum systems from the information theoretical points of view. We analyze a simple measure of correlations based on entropy (such measure was already investigated as the degree of entanglement by…

Quantum Physics · Physics 2012-09-13 Yuji Hirota , Dariusz Chruściński , Takashi Matsuoka , Masanori Ohya

Issues related to quantum entanglement in systems of indistinguishable particles, as discussed in the information theoretic approach, are extended to anyonic statistics. Local and non-local measurements discussed in this framework are…

Quantum Physics · Physics 2021-10-28 Ramadas N , V V Sreedhar

Coherence and entanglement are fundamental properties of quantum systems, promising to power the near future quantum computers, sensors and simulators. Yet, their experimental detection is challenging, usually requiring full reconstruction…

Quantum Physics · Physics 2017-08-01 Graeme Smith , John A. Smolin , Xiao Yuan , Qi Zhao , Davide Girolami , Xiongfeng Ma

Covariance matrices are a useful tool to investigate correlations and entanglement in quantum systems. They are widely used in continuous variable systems, but recently also for finite dimensional systems powerful entanglement criteria in…

Quantum Physics · Physics 2010-04-22 Oleg Gittsovich , Otfried Gühne

Entanglement of formation is an important measure of quantum entanglement. We present an experimental way to measure the entanglement of formation for arbitrary dimensional pure states. The measurement only evolves local quantum mechanical…

Quantum Physics · Physics 2012-01-31 Ming Li , Shao-Ming Fei

We discuss the problem of determining whether the state of several quantum mechanical subsystems is entangled. As in previous work on two subsystems we introduce a procedure for checking separability that is based on finding state…

Quantum Physics · Physics 2007-05-23 Andrew C. Doherty , Pablo A. Parrilo , Federico M. Spedalieri