Now showing items 1-20 of 98

    • A Combinatorial Approach to Nonlocality and Contextuality 

      Acín dal Maschio, Antonio; Fritz, Tobias; Leverrier, Anthony (Springer, 2015-03-01)
      Article
      Open Access
      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)
      Master thesis
      Open Access
      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 ...
    • Ag2ZnSnS4–ZnS core–shell colloidal quantum dots: a near-infrared luminescent material based on environmentally friendly elements 

      Saha, Avijit; Konstantatos, Gerasimos (RSC, 2021-05-07)
      Article
      Open Access
      Low cost, multinary colloidal quantum dots (QDs) based on environmentally friendly elements, with bright, narrow-width, tunable near-infrared (NIR) luminescence are promising alternatives to Cd and Pb chalcogenide QDs for ...
    • Almost quantum correlations 

      Navascués, Miguel; Guryanova, Yelena; Hoban, Matty J.; Acín dal Maschio, Antonio (Nature Publishing group, 2015-02-20)
      Article
      Open Access
      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)
      Master thesis
      Open Access
      [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 ...
    • Applications of machine learning to studies of quantum phase transitions 

      Malo Roset, Laura (Universitat Politècnica de Catalunya, 2019-09-06)
      Master thesis
      Open Access
      In the past years Machine Learning has shown to be a useful tool in quantum many-body physics to detect phase transitions. Being able to identify phases via machine learning introduces the question of how did the algorithm ...
    • 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
      Open Access
      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 ...
    • Bose polarons at finite temperature and strong coupling 

      Guenther, Nils Eric; Massignan, Pietro Alberto; Lewenstein, Maciej; Bruun, Georg (2018-02-01)
      Article
      Open Access
      A mobile impurity coupled to a weakly interacting Bose gas, a Bose polaron, displays several interesting effects. While a single attractive quasiparticle is known to exist at zero temperature, we show here that the spectrum ...
    • Bound states in the continuum in anisotropic structures 

      Gomis Bresco, Jordi; Artigas García, David; Pujol Closa, Maria del Pilar; Torner Sabata, Lluís (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Conference report
      Restricted access - publisher's policy
      We report theoretical and experimental observation of radiationless bound states in the continuum (BIC) in waveguiding anisotropic structures. BICs may have all possible polarizations and be the only possible boundstates ...
    • Bound states in the continuum in spin-orbit-coupled atomic systems 

      Kartashov, Yaroslav V.; Konotop, Vladimir V; Torner Sabata, Lluís (2017-09-14)
      Article
      Restricted access - publisher's policy
      We show that the interplay between spin-orbit coupling and Zeeman splitting in atomic systems can lead to the existence of bound states in the continuum (BICs) supported by trapping potentials. Such states have energies ...
    • Characterizing the spatio-temporal qubit traffic of a quantum intranet aiming at modular quantum computer architectures 

      Rodrigo Muñoz, Santiago; Spanò, Domenico; Bandic, Medina; Abadal Cavallé, Sergi; van Someren, Hans; Ovide, Anabel; Feld, Sebastian; García Almudever, Carmen; Alarcón Cot, Eduardo José (Association for Computing Machinery (ACM), 2022)
      Conference report
      Open Access
      Quantum many-core processors are envisioned as the ultimate solution for the scalability of quantum computers. Based upon Noisy Intermediate-Scale Quantum (NISQ) chips interconnected in a sort of quantum intranet, they ...
    • Coherent control of a superconducting quantum bit 

      Luque Merino, Rafael (Universitat Politècnica de Catalunya, 2019-09-06)
      Master thesis
      Open Access
      Transmon qubits are at the forefront of solid state platforms for quantum computing. In this thesis, results obtained from the experimental study of a transmon qubit in a 3D cavity are presented. A complete view of the ...
    • Detection of nonlocality with two-body correlation functions 

      Aloy López, Albert (Universitat Politècnica de Catalunya, 2015-09-10)
      Master thesis
      Open Access
      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 ...
    • Development of hole selective contacts on p-type c-Ge substrates 

      Lladós Cos, Òscar (Universitat Politècnica de Catalunya, 2020-12)
      Master thesis
      Open Access
      Thermophotovoltaic devices convert heat to electricity by absorbing infra-red photons with low energies. In order to do so semiconductors materials with low band-gap are needed. The crystalline Germanium (cGe) is an ...
    • Dicke superradiance in atomic arrays: impact of dimensionality 

      Sierra Garzo, Eric (Universitat Politècnica de Catalunya, 2021-10-01)
      Bachelor thesis
      Open Access
      Covenantee:   Columbia University
      Els efectes colectius són un àmbit de creixent interès en l'estudi de les interaccions llum-matèria a nivell quàntic. Aquest treball es centra en un d'aquests efectes conegut com la superradiància de Dicke, en la qual un ...
    • Dynamic structure factor of liquid He 4 across the normal-superfluid transition 

      Ferré Porta, Guillem; Boronat Medico, Jordi (2016-03-08)
      Article
      Open Access
      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 ...
    • Dynamics of equilibration and collisions in ultradilute quantum droplets 

      Cikojevic, Viktor; Vranješ Markic, Leandra; Barranco Gómez, Manuel; Ancilotto, F.; Boronat Medico, Jordi (American Physical Society, 2021-12-01)
      Article
      Open Access
      Employing time-dependent density-functional theory, we have studied dynamical equilibration and binary head-on collisions of quantum droplets taking as a case of study droplets made of a 39K-39K Bose mixture. The phase ...
    • Eina de representació de funcions d'ona quàntiques en 3D 

      Armada Ruiz, Alvaro (Universitat Politècnica de Catalunya, 2022-10-18)
      Bachelor thesis
      Open Access
      La física quàntica és un tema molt complex, que és la base per a la comprensió dels fenòmens naturals. Aquesta explica elements com l'àtom, l'enllaç químic... Ara bé, encara que descriu el món en una escala atòmica podem ...
    • Entanglement and non-locality of pure quantum states. 

      Sainz, Ana Belén (Universitat Politècnica de Catalunya, 2010-07-19)
      Master thesis
      Open Access
      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 ...
    • Explorations of thermodynamics and information in quantum field theory 

      Teixidó Bonfill, Adam (Universitat Politècnica de Catalunya, 2020-05-20)
      Bachelor thesis
      Open Access
      Covenantee:   Institute for Quantum Computing / University of Waterloo
      Podria dir-se que la termodinàmica ha sigut una de les rames més poderoses de la física, i la més universal per la seva varietat d'aplicacions. Des de motors de vapor fins a forats negres, les lleis de la termodinàmica ...