Now showing items 1-20 of 65

  • Applications of a quantum random number generator to simulations in condense matter physics 

    Guigó Corominas, Guillem (Universitat Politècnica de Catalunya, 2018-10-15)
    Master thesis
    Open Access
    Covenantee:  Institut de Ciències Fotòniques (ICFO)
    We study the importance of the quality of random numbers in Monte Carlo simulations of 2D Ising systems. Simulations are carried out at critical temperature to find the dynamic scaling law of the linear relaxation time. ...
  • A super frequency-shifter: enhancing the capabilities of acousto-optic modulators 

    Salazar Serrano, Luis José (Universitat Politècnica de Catalunya, 2012-09-06)
    Master thesis
    Open Access
    [ANGLÈS] We put forward a new scheme to enhance the capabilities of currently available acousto-optic frequency shifters (AOFS) by making use of the idea of weak value amplification. The key result of our approach is that ...
  • Characterization of a quantum frequency converter for quantum repeater applications 

    Fernandez Gonzalvo, Xavier (Universitat Politècnica de Catalunya, 2012-09-03)
    Master thesis
    Open Access
    [ANGLÈS] Quantum frequency conversion of quantum memory compatible photons to telecom wavelength is a requirement for the implementation of scalable quantum repeaters, a key ingredient for long distance quantum communications ...
  • Classical simulation of restricted quantum computations 

    Nebhwani, Mrityunjaya (Universitat Politècnica de Catalunya, 2013-09-09)
    Master thesis
    Open Access
    [ANGLÈS] We study restricted models of measurement-based quantum computation; and we investigate whether their output probability distributions can be sampled from efficiently on a classical computer. We find that even for ...
  • Coherence-based quantum random number generator 

    Álvarez Velásquez, Juan Rafael (Universitat Politècnica de Catalunya, 2018-08-27)
    Master thesis
    Open Access
    We consider the random change of the phase of a laser as the physical source of randomness that allows the implementation a new type of quantum random number generator (QRNG) . We analyze the phase noise model of a laser ...
  • Correlations and coherence: an experimental proposal 

    Sendra Molins, Lluc (Universitat Politècnica de Catalunya, 2017-10-24)
    Bachelor thesis
    Open Access
    We propose and realize a variation of Mandel's experiment where the Englert's inequality can be demonstrated. This is a relation of the coherence and the which-way information, which is one of the most fundamental results ...
  • Demonstration of a highly-sensitive tunable beam displacer with no use of beam deflection based on the concept of weak value amplification 

    Salazar Serrano, Luis Jose; Guzman, David A; Valencia, Alejandra; Pérez Torres, Juan (2015-04-10)
    Article
    Restricted access - publisher's policy
    We report the implementation of a highly sensitive tunable beam displacer based on the concept of weak value amplification, that allows to displace the centroid of a Gaussian beam a distance much smaller than its beam width ...
  • Design and construction of optical superlattices for a quantum gas experiment 

    Sastre Pellicer, Jordi (Universitat Politècnica de Catalunya, 2015-10)
    Bachelor thesis
    Open Access
    In recent years ultracold atomic gases have emerged as a new and promising platform for exploring the physics of quantum many-body systems, allowing researchers to revisit fundamental problems of condensed-matter physics ...
  • Detection loophole attacks on semi-device-independent quantum and classical protocols 

    Dall’Arno, Michele; Passaro, Elsa; Gallego, Rodrigo; Pawlowski, Marcin; Acín, Antonio (Rinton Press, 2015-01-01)
    Article
    Open Access
    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 ...
  • 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
    Open Access
    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. ...
  • Detection of graphene motion through light-matter interactions 

    Schädler, Kevin Gerd (Universitat Politècnica de Catalunya, 2012-09-06)
    Master thesis
    Open Access
    [ANGLÈS] In this thesis, we study both experimentally and theoretically the optical detection of the motion of graphene membranes based on fluorescence quenching of the emitters close to graphene. Fluorescence quenching ...
  • Detection of Zak phases and topological invariants in a chiral quantum walk of twisted photons 

    Cardano, Filippo; D'Errico, Alessio; dauphin, Alexandre; Maffei, Maria; Piccirillo, Bruno; de Lisio, Corrado; de Filippis, Guido; Cataudella, Vittorio; Santamato, Enrico; Marrucci, Lorenzo; Lewenstein, Maciej; Massignan, Pietro Alberto (2017)
    Article
    Open Access
    Topological insulators are fascinating states of matter exhibiting protected edge states and robust quantized features in their bulk. Here we propose and validate experimentally a method to detect topological properties ...
  • Development of a fluorescence imaging system for a quantum gas experiment 

    Sanz Sánchez, Julio (Universitat Politècnica de Catalunya, 2015-09-10)
    Master thesis
    Open Access
    Covenantee:  Universitat Autònoma de Barcelona / Institut de Ciències Fotòniques (ICFO) / Universitat de Barcelona
    In this report we present a technique for imaging the momentum distribution of an ultracold atomic gas in 3D and with single atom resolution. We describe the first experimental steps taken to implement it in a quantum gas ...
  • Diagrammatic expansions of Hubbard models 

    Losada Sosnovsky, Juan Manuel (Universitat Politècnica de Catalunya, 2016-06-19)
    Bachelor thesis
    Open Access
    Optical lattice are periodic structures made of light, they are formed by the interference of laser beams producing standing waves. The depth and the periodicity of the optical lattice can be highly controlled, therefore, ...
  • Digital coherent receiver for orbital angular momentum demultiplexing 

    Belmonte Molina, Aniceto; Pérez Torres, Juan (2013-01-15)
    Article
    Open Access
    We put forward a type of receiver for coherent detection of the photon orbital angular momentum (OAM). A coherent array receiver, consisting of multiple subapertures, with each subaperture coupled to a single-mode fiber, ...
  • Dynamics of a Bose Einstein condensate in a ring potential 

    Pino Quintana, Hernán (Universitat Politècnica de Catalunya / Universitat Autònoma de Barcelona, 2012-09-04)
    Master thesis
    Open Access
    [ANGLÈS] We have addressed the dynamics of a repulsive interacting 87 Rb Bose Einstein condensate (BEC) in a ring potential trap. Our study has been focused in the analysis of the interference pattern that arises by the ...
  • Dynamics of matter wave solitons 

    Polo Gómez, Juan (Universitat Politècnica de Catalunya / Universitat Autònoma de Barcelona, 2012-09-04)
    Master thesis
    Open Access
    [ANGLÈS] We study the implementation of a matter wave bright soliton interferometer formed by a Gaussian potential barrier placed at the center of a harmonic trap potential. After numerically evaluating the transmission ...
  • Efficient generation of new optical wavelengths by means of second harmonic generation in AlGaAs Bragg reflection waveguides 

    Valles Mari, Adam (Universitat Politècnica de Catalunya, 2011-09-19)
    Master thesis (pre-Bologna period)
    Open Access
    English: In this project has been designed and implemented a setup to produce the nonlinear process of the second harmonic generation (SHG) in Bragg reflection waveguides (BRW). Starting with the adjustment of a tunable ...
  • Efficient heralding of polarization-entangled photons from type-0 and type-II spontaneous parametric downconversion in periodically poled KTiOPO 4 

    Steinlechner, Fabian; Gilaberte, Marta; Jofre, Marc; Scheidl, Thomas; Pérez Torres, Juan; Pruneri, Valerio; Ursin, Rupert (2014-09-01)
    Article
    Restricted access - publisher's policy
    Ultrabright sources of entangled photon pairs with high heralding efficiency are an important step in the pursuit of high-bit-rate entanglement-base quantum key distribution, as well as an enabling tool for loss-sensitive ...
  • Entangled Photon Source for Single Molecule Microscopy 

    Abbasi Zargaleh, Soroush (Universitat Politècnica de Catalunya, 2013-02-11)
    Master thesis
    Open Access
    [ANGLÈS] This paper presents experimental implementation of highly correlated photons for single molecules microscopy application. We designed and built a Type-II Spontaneous Parametric Down Conversion (SPDC) photon pair ...