Search results for: separable states - Bridge of Knowledge

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Search results for: separable states

Search results for: separable states

  • Can Communication Power of Separable Correlations Exceed That of Entanglement Resource?

    Publication

    - PHYSICAL REVIEW LETTERS - Year 2014

    The scenario of remote state preparation with a shared correlated quantum state and one bit of forward communication [B. Dakić et al., Nat. Phys. 8, 666 (2012)] is considered. Optimization of the transmission efficiency is extended to include general encoding and decoding strategies. The importance of the use of linear fidelity is recognized. It is shown that separable states cannot exceed the efficiency of entangled states by...

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  • Broadcast copies reveal the quantumness of correlations

    Publication

    - PHYSICAL REVIEW A - Year 2009

    We study the quantumness of bipartite correlations by proposing a quantity that combines a measure of total correlations-mutual information-with the notion of broadcast copies-i.e., generally nonfactorized copies-of bipartite states. By analyzing how our quantity increases with the number of broadcast copies, we are able to classify classical, separable, and entangled states. This motivates the definition of the broadcast regularization...

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  • All Nonclassical Correlations Can Be Activated into Distillable Entanglement

    Publication
    • M. Piani
    • S. Gharibian
    • G. Adesso
    • J. Calsamigilia
    • P. Horodecki
    • A. Winter

    - PHYSICAL REVIEW LETTERS - Year 2011

    We devise a protocol in which general nonclassical multipartite correlations produce a physically relevant effect, leading to the creation of bipartite entanglement. In particular, we show that the relative entropy of quantumness, which measures all nonclassical correlations among subsystems of a quantum system, is equivalent to and can be operationally interpreted as the minimum distillable entanglement generated between the system...

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  • Inseparability criteria based on matrices of moments

    Publication

    - PHYSICAL REVIEW A - Year 2009

    Inseparability criteria for continuous and discrete bipartite quantum states based on moments of annihilationand creation operators are studied by developing the idea of Shchukin-Vogel criterion Phys. Rev. Lett. 95,230502 2005. If a state is separable, then the corresponding matrix of moments is separable too. Thus, wederive generalized criteria based on the separability properties of the matrix of moments. In particular, acriterion...

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  • Sudden death of effective entanglement

    Publication

    - PHYSICAL REVIEW A - Year 2010

    Sudden death of entanglement is a well-known effect resulting from the finite volume of separable states. We study the case when the observer has a limited measurement capability and analyze the effective entanglement (i.e., entanglement minimized over the output data). We show that in the well-defined system of two quantum dots monitored by single-electron transistors, one may observe a sudden death of effective entanglement when...

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  • Collective Uncertainty Entanglement Test

    Publication

    - PHYSICAL REVIEW LETTERS - Year 2011

    For a given pure state of a composite quantum system we analyze the product of its projections onto aset of locally orthogonal separable pure states. We derive a bound for this product analogous to theentropic uncertainty relations. For bipartite systems the bound is saturated for maximally entangled statesand it allows us to construct a family of entanglement measures, we shall call collectibility. As thesequantities are experimentally...

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  • From unextendible product bases to genuinely entangled subspaces

    Publication

    - PHYSICAL REVIEW A - Year 2018

    Unextendible product bases (UPBs) are interesting mathematical objects arising in composite Hilbert spaces that have found various applications in quantum information theory, for instance in a construction of bound entangled states or Bell inequalities without quantum violation. They are closely related to another important notion, completely entangled subspaces (CESs), which are those that do not contain any fully separable pure...

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  • Theory versus experiment for vacuum Rabi oscillations in lossy cavities

    Publication

    The 1996 experiment by Brune et al. [Phys. Rev. Lett. 76, 1800 (1996)] on vacuum Rabi oscillation is analyzed by means of alternative models of atom-reservoir interaction. Agreement with experimental Rabi oscillation data can be obtained if one defines jump operators in the dressed-state basis and takes into account thermal fluctuations between dressed states belonging to the same manifold. Such low-frequency transitions could...

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  • On structural physical approximations and entanglement breaking maps

    Publication

    - JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL - Year 2011

    Very recently, a conjecture saying that the so-called structural physical approximations (SPAs) to optimal positive maps (optimal entanglement witnesses) give entanglement breaking (EB) maps (separable states) has been posed (Korbicz et al 2008 Phys. Rev. A 78 062105). The main purpose of this contribution is to explore this subject. First, we extend the set of entanglement witnesses supporting the conjecture. Then, we ask whether...

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  • Hidden Tensor Structures

    Publication

    - ENTROPY - Year 2024

    Any single system whose space of states is given by a separable Hilbert space is automatically equipped with infinitely many hidden tensor-like structures. This includes all quantum mechanical systems as well as classical field theories and classical signal analysis. Accordingly, systems as simple as a single one-dimensional harmonic oscillator, an infinite potential well, or a classical finite-amplitude signal of finite duration...

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  • ON THE NON-LOCALITY OF TRIPARTITE NON-SINGALING BOXES EMERGING FROM WIRINGS

    Publication

    - QUANTUM INFORMATION & COMPUTATION - Year 2015

    It has been recently shown, that some of the tripartite boxes admittin g bilocal decom- position, lead to non-locality under wiring operation applied to t wo of the subsystems [R. Gallego et al. Physical Review Letters 109 , 070401 (2012)]. In the following, we study this phenomenon quantitatively. Basing on the known classes of bo xes closed un- der wirings, we introduce multipartite monotones which are count erparts of bipartite ones...

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  • Convex set of quantum states with positive partial transpose analysed by hit and run algorithm

    Publication
    • K. Szymański
    • B. Collins
    • T. Szarek
    • K. Życzkowski

    - Journal of Physics A-Mathematical and Theoretical - Year 2017

    The convex set of quantum states of a composite K×K system with positive partial transpose is analysed. A version of the hit and run algorithm is used to generate a sequence of random points covering this set uniformly and an estimation for the convergence speed of the algorithm is derived. For K >3 or K=3 this algorithm works faster than sampling over the entire set of states and verifying whether the partial transpose is positive....

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