Now showing items 1-20 of 21

  • 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 ...
  • 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. ...
  • 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 ...
  • Complex systems for quantum technologies 

    Braungardt, Sibylle (Universitat Politècnica de Catalunya, 2011-07-12)
    Doctoral thesis
    Open Access
  • Detection of quantum phase transitions via machine learning algorithms 

    Pérez Díaz, Joel (Universitat Politècnica de Catalunya, 2019-08-31)
    Master thesis
    Open Access
    A Neural Network is trained to classify Mott Insulator and Superfluid phases in an optical lattice using data generated with Diffusion Monte Carlo algorithms (DMC). The trained model is used to predict the phase transition ...
  • Dynamics of spinor fermions 

    Ebling, Ulrich (Universitat Politècnica de Catalunya, 2014-11-03)
    Doctoral thesis
    Open Access
    Ultracold atomic gases have established themselves as quantum systems, which are clean and offer a high degree of control over crucial parameters. They are well isolated from their environment and thus offer the possibility ...
  • Exact diagonalization studies of quantum simulators 

    Raventós Ribera, David (Universitat Politècnica de Catalunya, 2019-04-15)
    Doctoral thesis
    Open Access
    Understand and tame complex quantum mechanical systems to build quantum technologies is one of the most important scientific endeavour nowadays. In this effort, Atomic, molecular and Optical systems have clearly played a ...
  • Experimental evidence for the quantum condensation of ultracold dipolar excitons 

    Alloing, Mathieu (Universitat Politècnica de Catalunya, 2014-05-28)
    Doctoral thesis
    Open Access
    In this thesis, we report experimental evidence of a "gray" condensate of excitons, as predicted theoretically by M. Combescot et al. Most importantly, the condensate is characterized by the macroscopic population of dark ...
  • Nonergordic Subdiffusion of a Random-walker from Interactions with Heterogeneous Partners 

    Muñoz Gil, Gorka (Universitat Politècnica de Catalunya, 2016-09-08)
    Master thesis
    Open Access
    Understanding the motion of particles in biological systems is key in many applications such as drug precision delivery, living-cells characterization, etc. The dynamics of a particle in many of these systems is often ...
  • Optical emulator of two atoms in a double well 

    Fabra Ruiz, Arnau (Universitat Politècnica de Catalunya, 2019-09-09)
    Master thesis
    Open Access
    We show that optical fibers with an inhomogeneous refractive index profile and thin metallic slabs can be used to simulate a one dimensional system of two interacting particles in a double well. We first study the single ...
  • Quantum Brownian motion revisited : extensions and applications 

    Lampo, Aniello (Universitat Politècnica de Catalunya, 2018-10-02)
    Doctoral thesis
    Open Access
    Quantum Brownian motion represents a paradigmatic model of open quantum system, namely a system which cannot be treated as an isolated one, because of the unavoidable interaction with the surrounding environment. In this ...
  • Quantum gauge theory simulation with ultracold atoms 

    Zamora, Alejandro (Universitat Politècnica de Catalunya, 2014-12-15)
    Doctoral thesis
    Open Access
    The study of ultracold atoms constitutes one of the hottest areas of atomic, molecular, and optical physics and quantum optics. The experimental and theoretical achievements in the last three decades in the control and ...
  • Quantum-optical analysis of high-order harmonic generation 

    Rivera Deán, Javier (Universitat Politècnica de Catalunya, 2019-09-09)
    Master thesis
    Open Access
    High-order harmonic generation is a highly nonlinear phenomenon in which ultraviolet photons are generated when an atom is subjected to a high-intensity infrared laser field. This process has been extensively studied, but ...
  • Quantum simulations of attosecond physics 

    Rahman, Masudur (Universitat Politècnica de Catalunya, 2019-09-09)
    Master thesis
    Open Access
    We develop a numerical simulator to solve the time-dependent Schrödinger equation (TDSE) to simulate strong field ionization of a single electron under the influence of a one-dimensional separable potential. We use the ...
  • Quantum simulations with ultracold atoms: beyond standard optical lattices 

    Hauke, Philipp Hans-Jürgen (Universitat Politècnica de Catalunya, 2013-04-05)
    Doctoral thesis
    Open Access
    Many outstanding problems in quantum physics, such as high-Tc superconductivity or quark confinement, are still - after decades of research - awaiting commonly accepted explanations. One reason is that such systems are ...
  • Simulation and bulk detection of topological phases of matter 

    Maffei, Maria (Universitat Politècnica de Catalunya, 2019-01-29)
    Doctoral thesis
    Open Access
    Differently from the majority of the other phases of matter, which are characterized by local order parameters, the topological phases are characterized by integer or semi-integer numbers, the topological invariants, which ...
  • Spectral evidence for a condensate of dark excitons in a trap 

    Beian, Mussie (Universitat Politècnica de Catalunya, 2016-06-22)
    Doctoral thesis
    Open Access
    Spatially indirect excitons, being composite bosons, are attractive candidates to explore correlated many-body systems. They possess an inherent large electric dipole, a four-fold spin manifold, and can be studied via the ...
  • Strong-field processes in atoms and polyatomic molecules 

    Suárez Rojas, Noslen (Universitat Politècnica de Catalunya, 2018-01-23)
    Doctoral thesis
    Open Access
    Covenantee:  Università degli Studi di Firenze
    In this thesis, we develop a general theory to describe the dynamics of electrons that are ionized when an atom or molecule is exposed to a strong low frequency laser field. Our approach extends and improves the well-established ...
  • Ultracold atoms in artificial gauge fields 

    Grass, Tobias (Universitat Politècnica de Catalunya, 2013-04-23)
    Doctoral thesis
    Open Access
    The present thesis studies a variety of cold atomic systems in artificial gauge fields. In the first part we focus on fractional quantum Hall effects, asking whether interesting topological states can be realized with cold ...
  • Ultracold atoms in optical lattices with long-range interactions and periodic driving 

    Tieleman, Olivier (Universitat Politècnica de Catalunya, 2013-03-08)
    Doctoral thesis
    Open Access
    This thesis contains theoretical research on ultracold quantum gases in spatially periodic potentials, featuring high-frequency periodic driving, long-range interactions, or both. The largest part features deep potentials ...