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Related papers: Remarks on Lewenstein-Sanpera Decomposition

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In this paper we use the \textit{concurrence vector}, as a measure of entanglement, and investigate lower and upper bounds on the concurrence of a superposition of bipartite states as a function of the concurrence of the superposed states.…

Quantum Physics · Physics 2016-04-19 Seyed Javad Akhtarshenas

A $q$-deformed Weyl-Heisenberg algebra is used to define a deformed displacement operator giving rise to a naturally normalized nonlinear coherent states type. Robust maximally entangled deformed coherent states are studied and the effect…

Quantum Physics · Physics 2019-09-24 Mohamed Taha Rouabah , Noureddine Mebarki

We propose that the entanglement of mixed states is characterised properly in terms of a probability density function $\mathcal{P}(\mathcal{E})$. There is a need for such a measure since the prevalent measures (such as \textit{concurrence}…

Quantum Physics · Physics 2007-05-23 Shanthanu Bhardwaj , V. Ravishankar

We present an abstract formulation of the so-called Innsbruck-Hannover programme that investigates quantum correlations and entanglement in terms of convex sets. We present a unified description of optimal decompositions of quantum states…

Quantum Physics · Physics 2009-11-07 D. Bruss , J. I. Cirac , P. Horodecki , F. Hulpke , B. Kraus , M. Lewenstein , A. Sanpera

In this paper, we find the necessary and sufficient condition for the maximal entanglement of the state, $ |\psi>=\mu|\alpha>|\beta>+\lambda|\alpha>|\delta>+ \rho|\gamma>|\beta>+\nu|\gamma>|\delta>,$ constructed by linearly independent…

Quantum Physics · Physics 2011-04-28 G. Najarbashi , Y. Maleki

We study entanglement distillability of bipartite mixed spin states under Wigner rotations induced by Lorentz transformations. We define weak and strong criteria for relativistic isoentangled and isodistillable states to characterize…

Quantum Physics · Physics 2009-11-11 L. Lamata , M. A. Martin-Delgado , E. Solano

In this article we investigate the unitary dynamics of squashed entanglement and concurrence measures in Werner state and maximally entangled mixed states (MEMS) under two different Hamiltonians. The aim of the present study is two fold.…

Quantum Physics · Physics 2021-09-15 Kapil K. Sharma , Suprabhat Sinha

The reduction criterion is a well known necessary condition for separable states, and states violating this condition are entangled and also 1-distillable. In this paper we introduce a new set of necessary conditions for separability of…

Quantum Physics · Physics 2009-11-11 William Hall

Hilbert-Schmidt distance reduces to Euclidean distance in Bell decomposable states. Based on this, entanglement of these states are obtained according to the protocol proposed in Ref. [V. Vedral et al, Phys. Rev. Lett. 78, 2275 (1995)] with…

Quantum Physics · Physics 2007-05-23 S. J. Akhtarshenas , M. A. Jafarizadeh

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

We study the entanglement feature of the ground state of a system composed of spin 1 and 1/2 parts. The concurrence vector is shown to be consistent with the measurement of von Neumann entropy for such system. In the light of the ground…

Quantum Physics · Physics 2007-05-23 You-Quan Li , Guo-Qiang Zhu , Xue-An Zhao

We introduce generalization of the recently proposed \textit{Latent Entropy} (L-entropy) \cite{Basak:2024uwc} as a refined measure of genuine multipartite entanglement (GME) in pure states of $n$-party quantum systems. Generalized L-entropy…

High Energy Physics - Theory · Physics 2026-05-29 Byoungjoon Ahn , Jaydeep Kumar Basak , Keun-Young Kim , Gwon Bin Koo , Vinay Malvimat , Junggi Yoon

The basic question that is addressed in this paper is finding the closest separable state for a given entangled state, measured with the Hilbert Schmidt distance. While this problem is in general very hard, we show that the following…

Quantum Physics · Physics 2009-11-07 Frank Verstraete , Jeroen Dehaene , Bart De Moor

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

A new criterion necessary and sufficient for the separability of pure bipartite systems for arbitrary finite dimensions is demonstrated; and the corresponding finer quantitative measures or characterizations of entanglement (beyond mere…

Quantum Physics · Physics 2013-04-22 Che-Hsu Li

We provide a complete analysis of mixed three-qubit states composed of a GHZ state and a W state orthogonal to the former. We present optimal decompositions and convex roofs for the three-tangle. Further, we provide an analytical method to…

Quantum Physics · Physics 2007-05-23 Robert Lohmayer , Andreas Osterloh , Jens Siewert , Armin Uhlmann

We distinguish six classes of families of locally equivalent states in a straightforward scheme for classifying all 2-q-bit states; four of the classes consist of two subclasses each. The simple criteria that we stated recently for checking…

Quantum Physics · Physics 2015-06-26 Berthold-Georg Englert , Nasser Metwally

We study the closest disentangled state to a given entangled state in any system (multi-party with any dimension). We obtain the set of equations the closest disentangled state must satisfy, and show that its reduction is strongly related…

Quantum Physics · Physics 2007-05-23 Satoshi Ishizaka

This paper is an appendix to a previous paper: quant-ph/0101123 ``Relaxation Method for Calculating Quantum Entanglement", by Robert Tucci. For certain mixtures of Bell basis states, namely the Werner States, we use the theoretical…

Quantum Physics · Physics 2007-05-23 Robert R. Tucci

Computing the entanglement of formation of a bipartite state is generally difficult, but special symmetries of a state can simplify the problem. For instance, this allows one to determine the entanglement of formation of Werner states and…

Quantum Physics · Physics 2007-05-23 Kiran K. Manne , Carlton M. Caves