Quantum information theory: Enviaments recents

Ara es mostren els items 1-12 de 19

    • Split, but still attached 

      Cavalcanti, Daniel (Science, 2018-04-27)
      Article
      Accés obert
      Recent years have witnessed the beginning of the second quantum revolution, in which an impressive degree of control over quantum systems has led to several applications in quantum communication, computation, and sensing, ...

    • Secrecy in Prepare-and-Measure Clauser-Horne-Shimony-Holt Tests with a Qubit Bound 

      Woodhead, Erik; Pironio, Stefano (APS, 2015-10-06)
      Article
      Accés obert
      The security of device-independent (DI) quantum key distribution (QKD) protocols relies on the violation of Bell inequalities. As such, their security can be established based on minimal assumptions about the devices, but ...

    • Nonlocality in many-body quantum systems detected with two-body correlators 

      Tura, J.; Augusiak, Remigiusz; Sainz, A. B.; Lücke, B.; Klempt, C.; Lewenstein, Maciej; Acín dal Maschio, Antonio (Science Direct, 2015-07-30)
      Article
      Accés obert
      Contemporary understanding of correlations in quantum many-body systems and in quantum phase transitions is based to a large extent on the recent intensive studies of entanglement in many-body systems. In contrast, much ...

    • Detection of entanglement in asymmetric quantum networks and multipartite quantum steering 

      Cavalcanti, D.; Skrzypczyk, P.; Aguilar, G. H.; Souto Ribeiro, P. H.; Walborn, S. P. (Nature Publishing Group, 2015-08-03)
      Article
      Accés obert
      The future of quantum communication relies on quantum networks composed by observers sharing multipartite quantum states. The certification of multipartite entanglement will be crucial to the usefulness of these networks. ...

    • Locality of temperature in spin chains 

      Hernández-Santana, Senaida; Riera, Arnau; Hovhannisyan, Karen V.; Perarnau-Llobet, Martí; Tagliacozzo, Luca (IOP, 2015-08-18)
      Article
      Accés obert
      In traditional thermodynamics, temperature is a local quantity: a subsystem of a large thermal system is in a thermal state at the same temperature as the original system. For strongly interacting systems, however, the ...

    • Improved Quantum Magnetometry beyond the Standard Quantum Limit 

      Brask, J. B.; Chaves, R.; Kołodyński, J. (APS, 2015-07-22)
      Article
      Accés obert
      Under ideal conditions, quantum metrology promises a precision gain over classical techniques scaling quadratically with the number of probe particles. At the same time, no-go results have shown that generic, uncorrelated ...

    • Entanglement and Nonlocality are Inequivalent for Any Number of Parties 

      Augusiak, R.; Demianowicz, M.; Tura, J.; Acín dal Maschio, Antonio (APS, 2015-07-15)
      Article
      Accés obert
      Understanding the relation between nonlocality and entanglement is one of the fundamental problems in quantum physics. In the bipartite case, it is known that these two phenomena are inequivalent, as there exist entangled ...

    • Maximally Nonlocal Theories Cannot Be Maximally Random 

      Torre, Gonzalo de la; Hoban, Matty J.; Dhara, Chirag; Prettico, Giuseppe; Acín dal Maschio, Antonio (APS, 2015-04-22)
      Article
      Accés obert
      Correlations that violate a Bell inequality are said to be nonlocal; i.e., they do not admit a local and deterministic explanation. Great effort has been devoted to study how the amount of nonlocality (as measured by a ...

    • Thermodynamics of creating correlations: Limitations and optimal protocols 

      Bruschi, David Edward; Perarnau-Llobet, MartÍ; Friis, Nicolai; Hovhannisyan, Karen V; Huber, Marcus (APS, 2015-03-11)
      Article
      Accés obert
      We establish a rigorous connection between fundamental resource theories at the quantum scale. Correlations and entanglement constitute indispensable resources for numerous quantum information tasks. However, their establishment ...

    • Detection loophole attacks on semi-device-independent quantum and classical protocols 

      Dall’Arno, Michele; Passaro, Elsa; Gallego, Rodrigo; Pawlowski, Marcin; Acín dal Maschio, Antonio (Rinton Press, 2015-01-01)
      Article
      Accés obert
      Semi-device-independent quantum protocols realize information tasks – e.g. secure key distribution, random access coding, and randomness generation – in a scenario where no assumption on the internal working of the devices ...

    • Thermodynamic cost of creating correlations 

      Huber, Marcus; Perarnau-Llobet, Martí; Hovhannisyan, Karen V.; Skrzypczyk, Paul; Klöckl, Claude; Brunner, Nicolas; Acín dal Maschio, Antonio (IOP, 2015-06-10)
      Article
      Accés obert
      We investigate the fundamental limitations imposed by thermodynamics for creating correlations. Considering a collection of initially uncorrelated thermal quantum systems, we ask how much classical and quantum correlations ...

    • Passivity, complete passivity, and virtual temperatures 

      Skrzypczyk, Paul; Silva, Ralph; Brunner, Nicolas (OSA, 2015-05-19)
      Article
      Accés obert
      We give a simple and intuitive proof that the only states which are completely passive, i.e., those states from which work cannot be extracted even with infinitely many copies, are Gibbs states at positive temperatures. ...