1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia

Opción 1: Descargar recurso

Detalles del recurso


In this thesis, we will study the superfluidity of condensed atomic and photonic systems, through the manipulation of rotational states, such as vortices or persistent currents. We will study Bose-Einstein condensates both in the strongly-correlated regime, where models based on second quantization, like Bose-Hubbard model, will be required; and in weakly-interacting systems, where mean-field approximations will be accurate enough, and the system is described by means of the Gross-Pitaevskii equation. We will start with the analysis of the fundamental properties of Bose gases trapped in few-site lattices, such as the phase diagram, the condensed fractions and the entanglement. Concerning the phases, we will study the properties of the transitions between them and, in particular, their characteristic critical exponents. Afterwards, we will consider the sites of a lattice constituting a ring geometry and study the effect of manipulating the tunnelling rate between two of the wells. This kind of tunable link is called weak link, and we will analyze what happens in the mean-field approximation, in comparison with the strongly-correlated case. In both regimes we will observe that the weak link behaves as a key element in the system in order to generate superpositions of flow states. Moreover, in the mean-field case, we can identify an energy barrier that separates two current states (also known as winding number states), where solitonic states, i.e. states characterized by the presence of topological singularities, live. Such a barrier will be the origin of the appearance of a hysteresis cicle in processes of transfer between different winding number curves, called phase slips. After that, we will study two coherently-coupled components of a toroidally-trapped Bose-Einstein condensate. We will see that when we imprint a persistent current in one of the components, there is an angular momentum transfer between both components. This transfer can be identified as a phase slip event, and the tunability of the system allows it to behave as a robust qubit, due to the fact that states supported by currents are less fragile. In two-component condensates, it is possible to find a particular solitonic state called Josephson vortex. This state is characterized by a density depletion around a point with nonzero currents. Moreover, these states are energetically more favourable than dark soliton states, whose main difference with respect to Josephson vortices is the fact that dark solitons do not present currents. However, when spin-orbit coupling is added, dark soliton states are no longer possible, but Josephson vortices persist. In this thesis, we will see that these states decay through transversal excitations (i.e. snake instability), producing vortex-antivortex pairs, and their subsequent dynamical evolution depends on the initial orientation of the Josephson vortex. Finally, we will move to the field of polariton condensates. Polaritons are quasiparticles product of the coupling between photons and excitons (which are electron-hole excitations) in semiconductor microcavities. These particles can constitute an out-of-equilibrium (due to the short lifetime of polaritons) Bose-Einstein condensate described by the Gross-Pitaevskii-like equation for two components, because of the two polarization components inherent to the photonic nature of polaritons. The cavities where these condensates are created generate a spin-orbit coupling between the two polariton components, in such a way that current states with different orbital angular momentum are coupled. This yields to a phenomenon of spin-to-orbital angular momentum conversion that we will study in ring-trapped polariton condensates. At the end of this thesis, we will probe the superfluid properties of polariton condensates, by analyzing the response of the generated currents against the presence of disorder.

Pertenece a

TDX/TDR Tesis Doctorales en Red  


Gallemí Camacho, Albert - 

Id.: 71077757

Idioma: eng  - 

Versión: 1.0

Estado: Final

Tipo:  application/pdf -  166 p. - 

Palabras claveSuperfluïdesa - 

Tipo de recurso: info:eu-repo/semantics/doctoralThesis  -  info:eu-repo/semantics/publishedVersion  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

: ADVERTIMENT. L'accés als continguts d'aquesta tesi doctoral i la seva utilització ha de respectar els drets de la persona autora. Pot ser utilitzada per a consulta o estudi personal, així com en activitats o materials d'investigació i docència en els termes establerts a l'art. 32 del Text Refós de la Llei de Propietat Intel·lectual (RDL 1/1996). Per altres utilitzacions es requereix l'autorització prèvia i expressa de la persona autora. En qualsevol cas, en la utilització dels seus continguts caldrà indicar de forma clara el nom i cognoms de la persona autora i el títol de la tesi doctoral. No s'autoritza la seva reproducció o altres formes d'explotació efectuades amb finalitats de lucre ni la seva comunicació pública des d'un lloc aliè al servei TDX. Tampoc s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant als continguts de la tesi com als seus resums i índexs.

Formatos:  application/pdf -  166 p. - 

Requerimientos técnicos:  Browser: Any - 

Relación: [IsBasedOn] TDX (Tesis Doctorals en Xarxa)

Fecha de contribución: 13-mar-2018



Otros recursos que te pueden interesar

  1. Strategic Social Action Plan for MERCOSUR: Income transfer programs in the context of a neoliberal offensive Abstract This article analyzes the Strategic Social Action Plan for the Common Market of the South (...
  2. Authoritarian Governments and the Corrosion of the Social Protection Network in Brazil Abstract What are the impacts of the austerity reforms on the social protection network and the lega...
  3. State, Economy and Democracy in Brazil and Latin America
  4. Sensitivity analysis of a member under compression via Monte Carlo method The present work studies the application of a probabilistic methodology in the sensitivity analysis ...
  5. EIDINOW, Esther and KINDT, Julia (eds.). The Oxford Handbook of Ancient Greek Religion. Oxford and New York: Oxford University Press, 2015. p. xxii + 708. ISBN 9780199642038.

Otros recursos de la mismacolección

  1. Innovative targeted therapies for chemorefractory B-cell non-Hodgkin lymphomas Lymphomas are a heterogeneous group of tumors characterized by the proliferation of lymphocytes p...
  2. Cartografia i transformació del territori a Catalunya entre l’Antic Règim i la Revolució liberal (ss. XVIII-XIX): el paper de la família Soler La present investigació té l’objectiu de demostrar com, a partir de mitjan segle XVIII, la cartograf...
  3. Analysis and coordination of different mechanisms controlling tube elongation during the development of the embryonic system in Drosophila melanogaster The tracheal (respiratory) system of the Drosophila embryo is a network of interconnected epithelial...
  4. The role of species niche, species dispersal and landscape factors in the assembly of novel woody communities in metropolitan Mediterranean regions Biological diversity in a global scale has been threaten seriously by anthropogenic disturbances in ...
  5. Investigating Glial Contributions During Parkinson’s Disease Pathogenesis Using Patient-Specific iPSC-Derived Cells La malaltia de Parkinson (PD) s'associa amb la degeneració de les neurones dopaminèrgiques del mesen...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.