Now showing items 1-20 of 27

    • Ab-initio quantum Monte Carlo study of ultracold atomic mixtures 

      Cikojevic, Viktor (Universitat Politècnica de Catalunya, 2021-04-20)
      Doctoral thesis
      Open Access
      The properties of mixtures of Bose-Einstein condensates at T=0 have been investigated using quantum Monte Carlo (QMC) methods and Density Functional Theory (DFT) with the aim of understanding physics beyond the mean-field ...
    • Bose-Bose mixtures at finite temperature 

      Pascual López, Gerard (Universitat Politècnica de Catalunya, 2019-06-25)
      Bachelor thesis
      Restricted access - author's decision
    • Classical and quantum simulations of dislocations in crystals 

      Sempere Llagostera, Santiago (Universitat Politècnica de Catalunya, 2016-10-17)
      Bachelor thesis
      Open Access
      Covenantee:   University of New South Wales
    • Contact interactions in path integral Monte Carlo simulations 

      Cirauqui García, David (Universitat Politècnica de Catalunya, 2016-06-20)
      Bachelor thesis
      Open Access
      In very dilute Bose gases the full interatomic interaction can be well modeled by the s-wave scattering length defining the strength of a contact interaction. To introduce this kind of potential in quantum simulations is ...
    • Correlations in spin-orbit coupled ultracold quantum gases 

      Sánchez Baena, Juan (Universitat Politècnica de Catalunya, 2020-12-14)
      Doctoral thesis
      Open Access
      The main goal of this thesis is the computation of ground state properties of quantum many-body systems under Spin Orbit coupling (SOC) interactions out of the ultradilute regime. We present two approaches to fulfill this ...
    • 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 ...
    • 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 ...
    • Estudi de l'3He bidimensional amb mètodes de Monte Carlo quàntics 

      Grau Torre-Marín, Victor (Universitat Politècnica de Catalunya, 2001-07-16)
      Doctoral thesis
      Open Access
      de la tesi <br/>En aquest treball es presenta un estudi de l'3He a temperatura zero combinant les tècniques de Monte Carlo variacional (VMC) i la difusiva (DMC) amb nodes fixos (FN) i relaxació dels nodes (RN). <br/>L'estudi ...
    • 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 ...
    • Highly degenerate Fermi gases 

      Pera I Ferreruela, Jordi (Universitat Politècnica de Catalunya, 2020-10-09)
      Master thesis
      Open Access
      The aim of this work is to study a dilute Fermi gas, whether it has a spin 1/2 or it has a high degeneracy. The starting point is to calculate the energy of the system. However, as we are dealing with a many body system, ...
    • Microscopic description of confined bosonic dipolar quantum gases in two dimensions 

      Sánchez Baena, Juan (Universitat Politècnica de Catalunya, 2015-06-21)
      Bachelor thesis
      Open Access
      We present a microscopic description of the two dimensional quantum few body problem involving confined polarized bosons. Due to anisotropy of the dipolar interaction, the system presents an interesting behaviour in terms ...
    • Microscopic description of two dimensional dipolar quantum gases 

      Macía Rey, Adrián (Universitat Politècnica de Catalunya, 2015-02-13)
      Doctoral thesis
      Open Access
      A microscopic description of the many-body properties of anisotropic homogeneous gases of bosonic dipoles in two dimensions is presented and discussed. By changing the polarization angle with respect to the plane, we study ...
    • Mixtures of quantum dipolar gases: mixing and demixing 

      Pradas Rodriguez, Sergi (Universitat Politècnica de Catalunya, 2021-07-13)
      Bachelor thesis
      Open Access
      Presentem un anàlisis microscòpic de una barreja binaria de bosons dipolars a temperatura cero confinada en el pla xy amb moments dipolars (magnètics) permanents en la direcció z. Les interaccions dipol-dipol són repulsives ...
    • A Monte Carlo approach to statics and dynamics of quantum fluids 

      Ferré Porta, Guillem (Universitat Politècnica de Catalunya, 2017-09-16)
      Doctoral thesis
      Open Access
      The main objective of the thesis is to study static and/or dynamic properties of a set of quantum fluids by means of quantum Monte Carlo techniques, mainly using the path integral formalism to obtain results both at zero ...
    • Monte Carlo study of quantum phase transitions at zero temperature 

      Osychenko, Oleg N. (Universitat Politècnica de Catalunya, 2012-12-20)
      Doctoral thesis
      Open Access
      The Thesis is devoted to simulations of quantum phase transitions by means of Quantum Monte Carlo techniques. Quantum phase transition is a transition between phases at zero or low enough temperature, where quantum effects ...
    • Novel applications of Photonic Force Microscopy 

      Volpe, Giovanni (Universitat Politècnica de Catalunya, 2008-10-23)
      Doctoral thesis
      Open Access
      The ability of detecting farces and torques at the micro-and nano-scale is fundamental. When this Thesis started, various scanning probe techniques had already been developed to probe the mechanical properties of microsystems. ...
    • One dimensional quantum gases: from few to many 

      Amorós Binefa, Júlia (Universitat Politècnica de Catalunya, 2016-07-07)
      Bachelor thesis
      Open Access
      Covenantee:   Università degli studi di Trento
      The main objective of this project is to find the binding energy of an impurity interacting with a one-dimensional bosonic system of increasing size for different coupling strengths g. Both the bosons as well as the impurity ...
    • Path Integral Monte Carlo and Bose-Einstein condensation in quantum fluids and solids 

      Rota, Riccardo (Universitat Politècnica de Catalunya, 2011-12-20)
      Doctoral thesis
      Open Access
      Several microscopic theories point out that Bose-Einstein condensation (BEC), i.e., a macroscopic occupation of the lowest energy single particle state in many-boson systems, may appear also in quantum fluids and solids ...
    • Path integral Monte Carlo. Algorithms and applications to quantum fluids 

      Brualla Barberà, Llorenç (Universitat Politècnica de Catalunya, 2002-07-11)
      Doctoral thesis
      Open Access
      Path integral Monte Carlo (PIMC) is a method suitable for quantum liquid simulations at finite temperature. We present in this thesis a study of PIMC dealing with the theory and algorithms related to it, and then two ...
    • Probing the near-field optical response of plasmon nanostructures with two-photon luminescence microscopy 

      Ghenuche, Petru Virgil (Universitat Politècnica de Catalunya, 2009-04-02)
      Doctoral thesis
      Open Access
      Esta tesis describe el diseño, la fabricación y la caracterización óptica de sistemas plasmónicos resonantes capaces de confinar y aumentar campos de luz en la escala manométrica. En primer lugar, se utilizaron modelos ...