Ara es mostren els items 1-20 de 40

  • A Combinatorial Approach to Nonlocality and Contextuality 

    Acin, Antonio; Fritz, Tobias; Leverrier, Anthony (Springer, 2015-03-01)
    Article
    Accés obert
    So far, most of the literature on (quantum) contextuality and the Kochen– Specker theorem seems either to concern particular examples of contextuality, or be considered as quantum logic. Here, we develop a general formalism ...
  • A general framework for information-work interconvertibility in the quantum regime 

    Rodríguez Ramos, Constantino (Universitat Politècnica de Catalunya, 2016-09)
    Projecte Final de Màster Oficial
    Accés obert
    In this theoretical work we study three theorems that establish limitations to three basic processes in thermodynamics: an adiabatic process, an erasure process and a work extraction process. We propose a theoretical setting ...
  • Almost quantum correlations 

    Navascués, Miguel; Guryanova, Yelena; Hoban, Matty J.; Acín, Antonio (Nature Publishing group, 2015-02-20)
    Article
    Accés obert
    Quantum theory is not only successfully tested in laboratories every day but also constitutes a robust theoretical framework: small variations usually lead to implausible consequences, such as faster-than-light communication. ...
  • An experimental setup for gray molasses sub-Doppler cooling of potassium gases 

    Bosch Aguilera, Manel (Universitat Politècnica de Catalunya, 2014-09-09)
    Projecte Final de Màster Oficial
    Accés obert
    [ÀNGLÈS] An experimental setup for cooling a gas of potassium atoms below the Doppler limit is presented. This method is known as gray molasses cooling. It will be implemented using light blue light blue detuned with respect ...
  • Bloch oscillations in optical and Zeeman lattices in the presence of spin-orbit coupling 

    Kartashov, Yaroslav V.; Konotop, Vladimir V; Zezyulin, Dmitry A; Torner Sabata, Lluís (2016-11-18)
    Article
    Accés obert
    We address Bloch oscillations of a spin-orbit coupled atom in periodic potentials of two types: optical and Zeeman lattices. We show that in optical lattices the spin-orbit coupling allows controlling the direction of ...
  • Detection of nonlocality with two-body correlation functions 

    Aloy López, Albert (Universitat Politècnica de Catalunya, 2015-09-10)
    Projecte Final de Màster Oficial
    Accés obert
    Nonlocality detection in multipartite quantum systems is of great interest. The most popular tool to detect nonlocality in quantum systems are Bell inequalities. Most of the provided constructions of multipartite Bell ...
  • Dynamic structure factor of liquid He 4 across the normal-superfluid transition 

    Ferré Porta, Guillem; Boronat Medico, Jordi (2016-03-08)
    Article
    Accés obert
    We have carried out a microscopic study of the dynamic structure factor of liquid He4 across the normal-superfluid transition temperature using the path integral Monte Carlo method. The ill-posed problem of the inverse ...
  • Entanglement and non-locality of pure quantum states. 

    Sainz, Ana Belén (Universitat Politècnica de Catalunya, 2010-07-19)
    Projecte Final de Màster Oficial
    Accés obert
    We study the process of majorisation and interconversion of bipartite states, and apply the formalism for analysing the local and non-local content of pure bipartite entangled states. We proved that the states which are ...
  • External fluctuations in front propagation 

    Armero Rovira, J.; Sancho, Jose Maria; Casademunt, Jaume; Lacasta Palacio, Ana María; Ramírez de la Piscina Millán, Laureano; Sagués Mestre, Francesc (American Physical Society, 1996-04-01)
    Article
    Accés obert
    We study the effects of external noise in a one-dimensional model of front propagation. Noise is introduced through the fluctuations of a control parameter leading to a multiplicative stochastic partial differential equation. ...
  • First-passage times for a marginal state driven by colored noise 

    Ramírez de la Piscina Millán, Laureano; Sancho, Jose Maria (The American Physical Society, 1991-01-18)
    Article
    Accés obert
    The dynamical process through a marginal state (saddle point) driven by colored noise is studied. For small correlation time of the noise, the mean first-passage time and its variance are calculated using standard methods. ...
  • Física cuántica : interferencias, correlaciones y realidad 

    Scarani, Valerio (Iniciativa Digital Politècnica, 2015)
    Llibre
    Accés restringit a la comunitat UPC
    La física cuántica se ha erigido como uno de los pilares fundamentales sobre los cuales se asienta la física moderna. Es una puerta a un mundo fascinante, de características sorprendentes; un microcosmos regido por la ...
  • From poly(3,4-ethylenedioxythiophene) to poly(3,4-phenylenedioxythiophene) : impact of the ethylene bridge by the phenyl ring in the molecular propierties 

    Carrión Fajardo, Sergio (Universitat Politècnica de Catalunya, 2010-09)
    Projecte Final de Màster Oficial
    Accés restringit per decisió de l'autor
    The structural and electronic properties of poly(3,4-phenylenedioxythiophene) and poly(3,4- ethylenedioxythiophene) have been studied using quantum mechanical methods. Calculations have been performed considering a series ...
  • Highly efficient noise-assisted energy transport in classical oscillator systems 

    Leon Montiel, R de J.; Pérez Torres, Juan (2013-05)
    Article
    Accés obert
    Photosynthesis is a biological process that involves the highly-efficient transport of energy captured from the sun to a reaction center, where conversion into useful biochemical energy takes place. Even though one can ...
  • Llenguatges de Programació Quàntica 

    Marcos Pitarch, Eric (Universitat Politècnica de Catalunya, 2009-06)
    Projecte/Treball Final de Carrera
    Accés obert
    Aprofundir en els coneixements de computació quàntica, tant des del vessant de la física com des del vessant de la teoria de la computació, que em situïn en un punt de "pre-recerca". Tenir un mapa de les diferents ...
  • Local discrimination of rotationally invariant states 

    Ronco Bonvehi, Elio (Universitat Politècnica de Catalunya / Universitat Autònoma de Barcelona, 2010)
    Projecte Final de Màster Oficial
    Accés obert
    We provide lower bounds for the minimum error discrimination probability of multipartite rotationally invariant states using separable measurements. The separability of the measurement operators has been investigated, ...
  • Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres 

    Hensen, B.; Bernien, H.; Dréau, A. E.; Reiserer, A.; Kalb, N.; Blok, M. S.; Ruitenberg, J.; Vermeulen, R. F. L.; Schouten, R. N.; Abellán, C.; Amaya, W.; Pruneri, P.; Mitchell, Morgan W.; Markham, M.; Twitchen, D. J.; Elkouss, D.; Wehner, S.; Taminiau, T. H.; Hanson, R. (Nature Publishing Group, 2015-10-21)
    Article
    Accés restringit per política de l'editorial
    More than 50 years ago1, John Bell proved that no theory of nature that obeys locality and realism2 can reproduce all the predictions of quantum theory: in any local-realist theory, the correlations between outcomes of ...
  • Macroscopic Quantum State Analyzed Particle by Particle 

    Beduini, Federica A.; Zielińska, Joanna A.; Lucivero, Vito G.; Icaza Astiz, Yannick A. de; Mitchell, Morgan W. (ACS Publications, 2015-03-27)
    Article
    Accés obert
    Macroscopic quantum phenomena, e.g., superconductivity and squeezing, are believed to result from entanglement of macroscopic numbers of particles. We report the first direct study of this kind of entanglement: we use ...
  • Maximally Nonlocal Theories Cannot Be Maximally Random 

    Torre, Gonzalo de la; Hoban, Matty J.; Dhara, Chirag; Prettico, Giuseppe; Acín, 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 ...
  • Methods for solving 1D Stefan problems with application to contact melting 

    De Decker, Michelle (Universitat Politècnica de Catalunya, 2011-05)
    Projecte Final de Màster Oficial
    Accés obert
    Contact melting is the process during which a phase change material is placed in contact with a substrate that is at a temperature above the phase change temperature. This leads to melting of the phase change material and ...
  • Past, present and challenges in Yang-Mills theory 

    Tejedor Sánchez, Jose Luís (Universitat Politècnica de Catalunya, 2012-07)
    Projecte Final de Màster Oficial
    Accés obert
    Aquest treball tracta sobre les teories gauge de la física teòrica, la seva evolució des de el primer treball de Weyl (1918) fins als nostres dies tenint en compte el treball fonamental elaborat el 1954 per Yang i Mills que ...