Paweł Horodecki - Publikacje - MOST Wiedzy

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2018
2017
  • Amplifying the Randomness of Weak Sources Correlated With Devices
    Publikacja

    - IEEE TRANSACTIONS ON INFORMATION THEORY - 2017

    The problem of device-independent randomness amplification against no-signaling adversaries has so far been studied under the assumption that the weak source of randomness is uncorrelated with the (quantum) devices used in the amplification procedure. In this paper, we relax this assumption, and reconsider the original protocol of Colbeck and Renner using a Santha-Vazirani (SV) source. To do so, we introduce an SV-like condition...

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  • Generic appearance of objective results in quantum measurements
    Publikacja

    - PHYSICAL REVIEW A - 2017

    Measurement is of central interest in quantum mechanics as it provides the link between the quantum world and the world of everyday experience. One of the features of everyday experience is its robust, objective character, contrasting the delicate nature of quantum systems. Here we analyze in a completely model-independent way the celebrated von Neumann measurement process, using recent techniques of information flow, studied in...

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  • Information content of systems as a physical principle
    Publikacja

    - PHYSICAL REVIEW A - 2017

    To explain the conceptual gap between classical and quantum and other, hypothetical descriptions of the world, several principles have been proposed. So far, all these principles have not explicitly included the uncertainty relation. Here we introduce an information content principle ( ICP ) which represents a constrained uncertainty principle. The principle, by taking into account the encoding and decoding properties of a single physical...

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  • Monitoring of the Process of System Information Broadcasting in Time

    One of the problems of quantum physics is how a measurement turns quantum, noncopyable data, towards copyable classical knowledge. We use the quantum state discrimination in a central system model to show how its evolution leads to the broadcasting of the information, and how orthogonalization and decoherence factors allow us to monitor the distance of the state in question to the one perfectly broadcasting information, in any...

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  • Quantum Steering Inequality with Tolerance for Measurement-Setting Errors: Experimentally Feasible Signature of Unbounded Violation
    Publikacja

    - PHYSICAL REVIEW LETTERS - 2017

    uantum steering is a relatively simple test for proving that the values of quantum-mechanical measurement outcomes come into being only in the act of measurement. By exploiting quantum correlations, Alice can influence — steer — Bob ’ s physical system in a way that is impossible in classical mechanics, as shown by the violation of steering inequalities. Demonstrating this and similar quantum effects for systems of increasing size,...

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  • Superadditivity of two quantum information resources
    Publikacja

    - Science Advances - 2017

    Entanglement is one of the most puzzling features of quantum theory and a principal resource for quantum information processing. It is well known that in classical information theory, the addition of two classical information resources will not lead to any extra advantages. On the contrary, in quantum information, a spectacular phenomenon of the superadditivity of two quantum information resources emerges. It shows that quantum...

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  • Zero-knowledge convincing protocol on quantum bit is impossible
    Publikacja

    - Quantum Journal - 2017

    It is one of fundamental features of quantum formalism that o n one hand it provides a new infor- mation processing resources and on the other hand puts funda mental constraints on the processing of quantum information implying “no-go” theorems for cloni ng [1–3], bit commitment [4, 5] and deleting [6] in quantum theory. Here we ask about possibilit y of “zero knowledge” scenario which, for its simplicity, can be considered as...

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2016
  • Linear game non-contextuality and Bell inequalities—a graph-theoretic approach
    Publikacja

    - NEW JOURNAL OF PHYSICS - 2016

    We study the classical and quantum values of a class of one-and two-party unique games, that generalizes the well-known XOR games to the case of non-binary outcomes. In the bipartite case the generalized XOR(XOR-d) games we study are a subclass of the well-known linear games. We introduce a 'constraint graph' associated to such a game, with the constraints defining the game represented by an edge-coloring of the graph. We use the...

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  • No Quantum Realization of Extremal No-Signaling Boxes
    Publikacja

    - PHYSICAL REVIEW LETTERS - 2016

    The study of quantum correlations is important for fundamental reasons as well as for quantum communication and information processing tasks. On the one hand, it is of tremendous interest to derive the correlations produced by measurements on separated composite quantum systems from within the set of all correlations obeying the no-signaling principle of relativity, by means of information-theoretic principles. On the other hand,...

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  • Quantum communication complexity advantage implies violation of a Bell inequality
    Publikacja

    - PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA - 2016

    We obtain a general connection between a quantum advantage in communication complexity and non-locality. We show that given any protocol offering a (sufficiently large) quantum advantage in communication complexity, there exists a way of obtaining measurement statistics which violate some Bell inequality. Our main tool is port-based teleportation. If the gap between quantum and classical communication complexity can grow arbitrarily...

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  • Randomness Amplification under Minimal Fundamental Assumptions on the Devices
    Publikacja
    • R. Ramanathan
    • F. Brandão
    • K. Horodecki
    • M. Horodecki
    • P. Horodecki
    • H. Wojewódka

    - PHYSICAL REVIEW LETTERS - 2016

    Recently, the physically realistic protocol amplifying the randomness of Santha-Vazirani sources producing cryptographically secure random bits was proposed; however, for reasons of practical relevance, the crucial question remained open regarding whether this can be accomplished under the minimal conditions necessary for the task. Namely, is it possible to achieve randomness amplification using only two no-signaling components...

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  • Realistic noise-tolerant randomness amplification using finite number of devices
    Publikacja
    • F. Brandão
    • R. Ramanathan
    • A. Grudka
    • K. Horodecki
    • M. Horodecki
    • P. Horodecki
    • T. Szarek
    • H. Wojewódka

    - Nature Communications - 2016

    Randomness is a fundamental concept, with implications from security of modern data systems, to fundamental laws of nature and even the philosophy of science. Randomness is called certified if it describes events that cannot be pre-determined by an external adversary. It is known that weak certified randomness can be amplified to nearly ideal randomness using quantum-mechanical systems. However, so far, it was unclear whether randomness amplification...

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  • Sharp transitions in low-number quantum dots Bayesian magnetometry
    Publikacja

    - Scientific Reports - 2016

    We consider Bayesian estimate of static magnetic field, characterized by a prior Gaussian probability distribution, in systems of a few electron quantum dot spins interacting with infinite temperature spin environment via hyperfine interaction. Sudden transitions among optimal states and measurements are observed. Usefulness of measuring occupation levels is shown for all times of the evolution, together with the role of entanglement...

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  • Sharp transitions in low-number quantum dots Bayesian magnetometry
    Publikacja

    - Scientific Reports - 2016

    We consider Bayesian estimate of static magnetic field, characterized by a prior Gaussian probability distribution, in systems of a few electron quantum dot spins interacting with infinite temperature spin environment via hyperfine interaction. Sudden transitions among optimal states and measurements are observed. Usefulness of measuring occupation levels is shown for all times of the evolution, together with the role of entanglement...

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2015
  • Bound on Bell inequalities by fraction of determinism and reverse triangle inequality
    Publikacja
    • P. Joshi
    • K. Horodecki
    • M. Horodecki
    • P. Horodecki
    • R. Horodecki
    • B. Li
    • S. Szarek
    • T. Szarek

    - PHYSICAL REVIEW A - 2015

    It is an established fact that entanglement is a resource. Sharing an entangled state leads to nonlocal correlations and to violations of Bell inequalities. Such nonlocal correlations illustrate the advantage of quantum resources over classical resources. In this paper, we quantitatively study Bell inequalities with 2 × n inputs. As found in Gisin et al. [Int. J. Quantum. Inform. 05, 525 (2007)], quantum mechanical correlations...

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  • Distributed correlations and information flows within a hybrid multipartite quantum-classical system
    Publikacja

    - PHYSICAL REVIEW A - 2015

    Understanding the non-Markovian mechanisms underlying the revivals of quantum entanglement in the presence of classical environments is central in the theory of quantum information. Tentative interpretations have been given by either the role of the environment as a control device or the concept of hidden entanglement. We address this issue from an information-theoretic point of view. To this aim, we consider a paradigmatic tripartite...

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  • Generic emergence of classical features in quantum Darwinism
    Publikacja

    - Nature Communications - 2015

    Quantum Darwinism posits that only specific information about a quantum system that is redundantly proliferated to many parts of its environment becomes accessible and objective, leading to the emergence of classical reality. However, it is not clear under what conditions this mechanism holds true. Here we prove that the emergence of classical features along the lines of quantum Darwinism is a general feature of any quantum dynamics:...

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  • Method for universal detection of two-photon polarization entanglement
    Publikacja
    • K. Bartkiewicz
    • P. Horodecki
    • K. Lemr
    • A. Miranowicz
    • K. Życzkowski

    - PHYSICAL REVIEW A - 2015

    Detecting and quantifying quantum entanglement of a given unknown state poses problems that are fundamentally important for quantum information processing. Surprisingly, no direct (i.e., without quantum tomography) universal experimental implementation of a necessary and sufficient test of entanglement has been designed even for a general two-qubit state. Here we propose an experimental method for detecting a collective universal...

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  • Quantum metrology: Heisenberg limit with bound entanglement
    Publikacja

    - PHYSICAL REVIEW A - 2015

    Quantum entanglement may provide a huge boost in the precision of parameter estimation. However, quantum metrology seems to be extremely sensitive to noise in the probe state. There is an important still open question: What type of entanglement is useful as a resource in quantum metrology? Here we raise this question in relation to entanglement distillation. We provide a counterintuitive example of a family of bound entangled states...

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  • Quantum origins of objectivity
    Publikacja

    - PHYSICAL REVIEW A - 2015

    In spite of all of its successes, quantum mechanics leaves us with a central problem: How does nature create a bridge from fragile quanta to the objective world of everyday experience? Here we find that a basic structure within quantum mechanics that leads to the perceived objectivity is a so-called spectrum broadcast structure. We uncover this based on minimal assumptions, without referring to any dynamical details or a concrete...

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2014
  • Can Communication Power of Separable Correlations Exceed That of Entanglement Resource?
    Publikacja

    - PHYSICAL REVIEW LETTERS - 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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  • Characterizing the Performance of <span class="sc">xor</span> Games and the Shannon Capacity of Graphs
    Publikacja

    - PHYSICAL REVIEW LETTERS - 2014

    In this Letter we give a set of necessary and sufficient conditions such that quantum players of a two-party xor game cannot perform any better than classical players. With any such game, we associate a graph and examine its zero-error communication capacity. This allows us to specify a broad new class of graphs for which the Shannon capacity can be calculated. The conditions also enable the parametrization of new families of games...

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  • Constructive entanglement test from triangle inequality
    Publikacja

    - Journal of Physics A-Mathematical and Theoretical - 2014

    We derive a simple lower bound on the geometric measure of entanglement for mixed quantum states in the case of a general multipartite system. The main ingredient of the presented derivation is the triangle inequality applied to the root infidelity distance in the space of density matrices. The obtained bound leads to entanglement criteria with a straightforward interpretation. The proposed criteria provide an experimentally accessible,...

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  • Free randomness amplification using bipartite chain correlations
    Publikacja
    • A. Grudka
    • K. Horodecki
    • M. Horodecki
    • P. Horodecki
    • M. Pawłowski
    • R. Ramanathan

    - PHYSICAL REVIEW A - 2014

    A direct analysis of the task of randomness amplification from Santha-Vazirani sources using the violation of the chained Bell inequality is performed in terms of the convex combination of no-signaling boxes required to simulate quantum violation of the inequality. This analysis is used to find the exact threshold value of the initial randomness parameter from which perfect randomness can be extracted in the asymptotic limit of...

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  • Intrinsic asymmetry with respect to adversary: a new feature of Bell inequalities
    Publikacja

    It is known that the local bound of a Bell inequality is sensitive to the knowledge of the external observer about the settings statistics. Here we ask how that sensitivity depends on the structure of that knowledge. It turns out that in some cases it may happen that the local bound is much more sensitive to the adversaryʼs knowledge about the settings of one party than the other. Remarkably, there are Bell inequalities which are...

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  • Long-distance quantum communication over noisy networks without long-time quantum memory
    Publikacja
    • P. Mazurek
    • A. Grudka
    • M. Horodecki
    • P. Horodecki
    • J. Łodyga
    • Ł. Pankowski
    • A. Przysiężna

    - PHYSICAL REVIEW A - 2014

    The problem of sharing entanglement over large distances is crucial for implementations of quantum cryptography. A possible scheme for long-distance entanglement sharing and quantum communication exploits networks whose nodes share Einstein-Podolsky-Rosen (EPR) pairs. In Perseguers et al. [Phys. Rev. A 78, 062324 (2008)] the authors put forward an important isomorphism between storing quantum information in a dimension D and transmission...

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  • Necessary and Sufficient Condition for State-Independent Contextual Measurement Scenarios
    Publikacja

    - PHYSICAL REVIEW LETTERS - 2014

    The problem of identifying measurement scenarios capable of revealing state-independent contextuality in a given Hilbert space dimension is considered. We begin by showing that for any given dimension d and any measurement scenario consisting of projective measurements, (i) the measure of contextuality of a quantum state is entirely determined by its spectrum, so that pure and maximally mixed states represent the two extremes...

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  • Objectivity in a Noisy Photonic Environment through Quantum State Information Broadcasting
    Publikacja

    - PHYSICAL REVIEW LETTERS - 2014

    Recently, the emergence of classical objectivity as a property of a quantum state has been explicitly derived for a small object embedded in a photonic environment in terms of a spectrum broadcast form—a specific classically correlated state, redundantly encoding information about the preferred states of the object in the environment. However, the environment was in a pure state and the fundamental problem was how generic and robust...

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  • Quantifying Contextuality
    Publikacja
    • A. Grudka
    • K. Horodecki
    • M. Horodecki
    • P. Horodecki
    • R. Horodecki
    • P. Joshi
    • W. Kłobus
    • A. Wójcik

    - PHYSICAL REVIEW LETTERS - 2014

    Contextuality is central to both the foundations of quantum theory and to the novel information processing tasks. Despite some recent proposals, it still faces a fundamental problem: how to quantify its presence? In this work, we provide a universal framework for quantifying contextuality. We conduct two complementary approaches: (i) the bottom-up approach, where we introduce a communication game, which grasps the phenomenon of...

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  • Quantum-state transfer in spin chains via isolated resonance of terminal spins
    Publikacja

    - PHYSICAL REVIEW A - 2014

    We propose a quantum-state transfer protocol in a spin chain that requires only the control of the spins at the ends of the quantum wire. The protocol is to a large extent insensitive to inhomogeneity caused by local magnetic fields and perturbation of exchange couplings. Moreover, apart from the free evolution regime, it allows one to induce an adiabatic spin transfer, which provides the possibility of performing the transfer...

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  • Sensitivity of entanglement decay of quantum-dot spin qubits to the external magnetic field
    Publikacja

    - PHYSICAL REVIEW A - 2014

    We study the decay of entanglement of quantum-dot electron-spin qubits under hyperfine-interaction-mediated decoherence.We show that two-qubit entanglement of a single entangled initial state may exhibit decay characteristic of two disentanglement regimes in a single sample, when the externalmagnetic field is changed. The transition is manifested by the suppression of time-dependent entanglement oscillations which are superimposed...

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  • Strong Monogamies of No-Signaling Violations for Bipartite Correlation Bell Inequalities
    Publikacja

    - PHYSICAL REVIEW LETTERS - 2014

    The phenomenon of monogamy of Bell inequality violations is interesting both from the fundamental perspective as well as in cryptographic applications such as the extraction of randomness and secret bits. In this article, we derive new and stronger monogamy relations for violations of Bell inequalities in general no-signaling theories. These relations are applicable to the class of binary output correlation inequalities known as...

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  • The decay of quantum correlations between quantum dot spin qubits and the characteristics of its magnetic-field dependence
    Publikacja

    - EPL-EUROPHYS LETT - 2014

    We address the question of the role of quantum correlations beyond entanglement in the context of quantum magnetometry. We study the evolution of the rescaled variant of the geometric quantum discord of two electron-spin qubits interacting with an environment of nuclear spins via the hyperfine interaction. We have found that quantum correlations display a strong magnetic-field sensitivity which can be utilized for decoherence-driven...

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2013
  • Anomalous decay of quantum correlations of quantum-dot qubits
    Publikacja

    - PHYSICAL REVIEW A - 2013

    We study the evolution of quantum correlations, quantified by the geometric discord, of two excitonic quantum-dot qubits under the influence of the phonon environment. We show that the decay of these correlations differs substantially from the decay of entanglement. Instead of displaying sudden-death-type behavior, the geometric discord shows a tendency to undergo transitions between different types of decay, is sensitive to nonlocal...

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  • Conjectured strong complementary-correlations tradeoff
    Publikacja
    • A. Grudka
    • M. Horodecki
    • P. Horodecki
    • R. Horodecki
    • W. Kłobus
    • Ł. Pankowski

    - PHYSICAL REVIEW A - 2013

    We conjecture uncertainty relations that restrict correlations between the results of measurements performed by two separate parties on a shared quantum state. The first uncertainty relation bounds the sum of two mutual informations when one party measures a single observable and the other party measures one of two observables. The uncertainty relation does not follow from the Maassen-Uffink uncertainty relation and is much stronger...

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  • Experimental generation of complex noisy photonic entanglement
    Publikacja
    • K. Dobek
    • M. Karpiński
    • R. Demkowicz-Dobrzański
    • K. Banaszek
    • P. Horodecki

    - LASER PHYSICS - 2013

    We present an experimental scheme based on spontaneous parametric down-conversion to produce multiple-photon pairs in maximally entangled polarization states using an arrangement of two type-I nonlinear crystals. By introducing correlated polarization noise in the paths of the generated photons we prepare mixed-entangled states whose properties illustrate fundamental results obtained recently in quantum information theory, in particular those...

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  • Multiacces quantum communication and product higher rank numerical range

    In the present paper we initiate the study of the product higher rank numerical range. The latter, being a variant of the higher rank numerical range, is a natural tool for study- ing a construction of quantum error correction codes for multiple access channels. We review properties of this set and relate it to other numerical ranges, which were recently introduced in the literature. Further, the concept is applied to the construction...

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  • NO-BROADCASTING OF NON-SIGNALLING BOXES VIA OPERATIONS WHICH TRANSFORM LOCAL BOXES INTO LOCAL ONES
    Publikacja
    • P. Joshi
    • A. Grudka
    • K. Horodecki
    • M. Horodecki
    • P. Horodecki
    • R. Horodecki

    - QUANTUM INFORMATION & COMPUTATION - 2013

    We deal with families of probability distributions satisfying non-signalling condition, called non-signalling boxes and consider a class of operations that transform local boxes into local ones (the one that admit LHV model). We prove that any operation from this class cannot broadcast a bipartite non-local box with 2 binary inputs and outputs. We consider a function called anti-Robustness which can not decrease under these operations....

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  • Quantum mechanical which-way experiment with an internal degree of freedom
    Publikacja

    - Nature Communications - 2013

    For a particle travelling through an interferometer, the trade-off between the available which-way information and the interference visibility provides a lucid manifestation of the quantum mechanical wave-particle duality. Here we analyse this relation for a particle possessing an internal degree of freedom such as spin. We quantify the trade-off with a general inequality that paints an unexpectedly intricate picture of wave-particle...

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  • Separability in terms of a single entanglement witness
    Publikacja

    - PHYSICAL REVIEW A - 2013

    The separability problem is formulated in terms of a characterization of a single entanglement witness. More specifically, we show that any (in general multipartite) state rho is separable if and only if a specially constructed entanglement witness W-rho is weakly optimal, i.e., its expectation value vanishes on at least one product vector. Interestingly, the witness can always be chosen to be decomposable. Our result changes the...

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2012
  • Analytical progress on symmetric geometric discord: Measurement-based upper bounds
    Publikacja

    - PHYSICAL REVIEW A - 2012

    Quantum correlations may be measured by means of the distance of the state to the subclass ofstates having well defined classical properties. In particular, a geometric measure of asymmetricdiscord [Daki´c et al., Phys. Rev. Lett. 105, 190502 (2010)] was recently defined as the Hilbert-Schmidt distance of a given two-qubit state to the closest classical-quantum (CQ) correlated state.We analyze a geometric measure of symmetric...

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  • Convergence to equilibrium under a random Hamiltonian
    Publikacja
    • F. Brandao
    • P. Ćwikliński
    • M. Horodecki
    • P. Horodecki
    • J. Korbicz
    • M. Mozrzymas

    - PHYSICAL REVIEW E - 2012

    We analyze equilibration times of subsystems of a larger system under a random total Hamiltonian, in which the basis of the Hamiltonian is drawn from the Haar measure. We obtain that the time of equilibration is of the order of the inverse of the arithmetic average of the Bohr frequencies. To compute the average over a random basis, we compute the inverse of a matrix of overlaps of operators which permute four systems. We first...

  • Directed percolation effects emerging from superadditivity of quantum networks

    Entanglement-induced nonadditivity of classical communication capacity in networks consisting of quantum channels is considered. Communication lattices consisting of butterfly-type entanglement-breaking channels augmented, with some probability, by identity channels are analyzed. The capacity superadditivity in the network is manifested in directed correlated bond percolation which we consider in two flavors: simply directed and...

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  • Quantum privacy witness
    Publikacja

    - PHYSICAL REVIEW A - 2012

    While it is usually known that the mean value of a single observable is enough to detect entanglement or its distillability, the counterpart of such an approach in the case of quantum privacy has been missing. Here we develop the concept of a privacy witness, i.e., a single observable that may detect the presence of the secure key even in the case of bound entanglement. Then we develop the notion of secret-key estimation based...

  • Quantum-correlation breaking channels, broadcasting scenarios, and finite Markov chains
    Publikacja

    One of the classical results concerning quantum channels is the characterization of entanglementbreakingchannels [M. Horodecki et al., Rev. Math. Phys 15, 629 (2003)]. We address the questionwhether there exists a similar characterization on the level of quantum correlations which may gobeyond entanglement. The answer is fully affirmative in the case of breaking quantum correlationsdown to the, so called, QC (Quantum-Classical)...

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  • Schemes of transmission of classical information via quantum channels with many senders: Discrete- and continuous-variable cases
    Publikacja

    Superadditivity effects in the classical capacity of discrete multiaccess channels and continuous variable (CV) Gaussian MACs are analyzed. Several examples of the manifestation of superadditivity in the discrete case are provided, including, in particular, a channel which is fully symmetric with respect to all senders. Furthermore, we consider a class of channels for which input entanglement across more than two copies of the...

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