Now showing items 21-40 of 67

  • Highly efficient noise-assisted energy transport in classical oscillator systems 

    Leon Montiel, R de J.; Pérez Torres, Juan (2013-05)
    Article
    Open Access
    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 ...
  • Holographic imaging of nanometer-scale phase-separation during a phase transition 

    Valls Conesa, Jordi (Universitat Politècnica de Catalunya, 2019-09-09)
    Master thesis
    Open Access
    Quantum materials is a broad term used in condensed matter physics to define materials whose collective properties are governed by quantum behavior, which are challenging to understand. These materials are sensitive to ...
  • Klein's paradox and the relativistic d-shell interaction in R3 

    Mas Blesa, Albert (Mathematical Sciences Publishers, 2017-12-20)
    Article
    Open Access
    Under certain hypotheses of smallness on the regular potential V, we prove that the Dirac operator in Unexpected text node: 'R', coupled with a suitable rescaling of V, converges in the strong resolvent sense to the ...
  • Llenguatges de Programació Quàntica 

    Marcos Pitarch, Eric (Universitat Politècnica de Catalunya, 2009-06)
    Master thesis (pre-Bologna period)
    Open Access
    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)
    Master thesis
    Open Access
    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, Carlos, 1990-; 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
    Restricted access - publisher's policy
    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 Ada; Lucivero, Vito G.; Icaza Astiz, Yannick A. de; Mitchell, Morgan W. (ACS Publications, 2015-03-27)
    Article
    Open Access
    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
    Open Access
    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)
    Master thesis
    Open Access
    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 ...
  • Observation of the topological Anderson insulator in disordered atomic wires 

    Meier, Eric J.; An, Fangzhao Alex; dauphin, Alexandre; Maffei, Maria; Massignan, Pietro Alberto; Hughes, Taylor L.; Gadway, Bryce (2018-11-23)
    Article
    Open Access
    Topology and disorder have a rich combined influence on quantum transport. In order to probe their interplay, we synthesized one-dimensional chiral symmetric wires with controllable disorder via spectroscopic Hamiltonian ...
  • One-shot capacity bounds on the simultaneous transmission of classical and quantum information 

    Salek Shishavan, Farzin; Anshu, Anurag; Hsieh, Min-Hsiu; Jain, Rahul; Rodríguez Fonollosa, Javier (2019-10-07)
    Article
    Open Access
    We study the communication capabilities of a quan- tum channel under the most general channel model known as the one-shot model. Unlike classical channels that can only be used to transmit classical information (bits), a ...
  • Partículas huérfanas 

    Barceló Garcia, Miquel (1997-11)
    Article
    Open Access
  • Past, present and challenges in Yang-Mills theory 

    Tejedor Sánchez, Jose Luís (Universitat Politècnica de Catalunya, 2012-07)
    Master thesis
    Open Access
    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 ...
  • Phase diagram of a quantum Coulomb wire 

    Ferré Porta, Guillem; Astrakharchik, Grigori; Boronat Medico, Jordi (2015-12-09)
    Article
    Open Access
  • Physics and machine learning: Emerging paradigms 

    Martín Guerrero, José; Lisboa, Paulo J G; Vellido Alcacena, Alfredo (I6doc.com, 2016)
    Conference report
    Open Access
    Current research in Machine Learning (ML) combines the study of variations on well-established methods with cutting-edge breakthroughs based on completely new approaches. Among the latter, emerging paradigms from Physics ...
  • Quantifying multipartite nonlocality via the size of the resource 

    Curchod, Florian John; Gisin, Nicolas; Liang, Yeong-Cherng (APS Physics, 2015-01-30)
    Article
    Open Access
    The generation of (Bell-)nonlocal correlations, i.e., correlations leading to the violation of a Bell-like inequality, requires the usage of a nonlocal resource, such as an entangled state. When given a correlation (a ...
  • Quantum annealing of a hard combinatorial problem 

    Lecina Casas, Daniel (Universitat Politècnica de Catalunya, 2011-02-04)
    Master thesis
    Open Access
    We present the numerical results obtained using quantum annealing (QA) in a hard combinatorial problem: the coloring problem (q-COL) of an Erd˝os-R´enyi graph. We first propose a quantum coloring Hamiltonian, natural ...
  • Quantum control of population transfer and vibrational states via chirped pulses in four level density matrix equations 

    Afa, Iduabo John; Serrat Jurado, Carles (2016-11-15)
    Article
    Open Access
    We investigate the effect of chirped excitation and the excitation detuning on the coherent control of population transfer and vibrational states in a four-­--level system. Density matrix equations are studied for optimally ...
  • Quantum Error Correction - Decoders 

    Bordas Marchante, Eduard (Universitat Politècnica de Catalunya, 2019-09-09)
    Master thesis
    Open Access
    Error correction is used to correct any errors that may arise when sending any message, as errors are prone to appear due to noise. For classical codes, there are many decoders used, for example, belief propagation. ...
  • Quantum Many-Body Systems in 1D: One Dimensional Hydrogen 

    Vidal Arias, Alfredo José (Universitat Politècnica de Catalunya, 2015-06-22)
    Bachelor thesis
    Open Access
    The ground-state properties of one-dimensional spin polarized hydrogen, deuterium and tritium at zero temperature are obtained by means of Diffusion Monte Carlo calculations (DMC). The equations of state of the three ...