Sökning: "nonlinear Schrödinger equation"

Visar resultat 6 - 10 av 22 avhandlingar innehållade orden nonlinear Schrödinger equation.

  1. 6. The defocusing nonlinear Schrödinger equation with step-like oscillatory data

    Författare :Samuel Fromm; Jonatan Lenells; Alexander Tovbis; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Sammanfattning : The thesis at hand consists of three papers as well as an introductory chapter and a summary of results. The topic of the thesis is the study of the defocusing nonlinear Schrödinger equation with step-like oscillatory data. LÄS MER

  3. 7. Theoretical studies of lattice- and spin-polarons

    Författare :Nina Bondarenko; Olle Eriksson; Natalia Skorodumova; Manuel Pereiro; Maria Roser Valenti Vall; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polaron; Nonlinear Schrödinger Equation; Nonlocality; Solitons; Integrable systems; Quantum field theory low energy ; Electron-phonon interaction; Density functional theory; Electronic structure of atoms and molecules; Spin-polaron; Langevin equation; Transport properties; Hubbard model; Heisenberg lattice; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Theoretical studies of lattice- and spin-polarons are presented in this thesis, where the primary tool is ab-initio electronic structure calculations. The studies are performed with employment of a variety of analytical and computational methods. LÄS MER

  4. 8. Energy-conservative finite element methods for nonlinear Schrödinger equations

    Författare :Johan Wärnegård; Patrick Henning; Xavier Antoine; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tillämpad matematik och beräkningsmatematik; Applied and Computational Mathematics; Numerical Analysis; Numerisk analys;

    Sammanfattning : This thesis is devoted to numerical methods for nonlinear Schrödingerequations (NLSEs). These equations have applications in a variety offields such as optics, fluid dynamics, solid-state physics and, of course,quantum mechanics. Notably, the cubic NLSE describes the dynamics of Bose-Einstein condensates. LÄS MER

  5. 9. Nonlinear intrachannel distortion in high-speed optical transmission systems

    Författare :Pontus Johannisson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; all-optical regeneration; nonlinear optics; fiber optics; self-phase modulation; cross-phase modulation; ghost pulses; intrachannel four-wave mixing; timing jitter;

    Sammanfattning : The Kerr nonlinearity in optical fibres tends to generate signal distortion in dispersion-managed fibre-optic communication systems. Within a wavelength channel, the resulting intrachannel effects are timing jitter, i.e. LÄS MER

  7. 10. On Nonlinear Compensation Techniques for Coherent Fiber-Optical Channel

    Författare :Naga Vishnukanth Irukulapati; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; performance limits.; nonlinear compensation; factor graphs; fiber-optical communications; near-MAP detector; Digital backpropagation;

    Sammanfattning : Fiber-optical communication systems form the backbone of the internet, enabling global broadband data services. Over the past decades, the demand for high-speed communications has grown exponentially. One of the key techniques for the efficient use of existing bandwidth is the use of higher order modulation formats along with coherent detection. LÄS MER