Sökning: "quasiclassical theory"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden quasiclassical theory.

  1. 1. Mesoscopic superconductivity : quasiclassical approach

    Författare :Marek Ožana; Andrei Shelankov; Dierk Rainer; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mesoscopic superconductivity; quasiclassical theory; boundary conditions; multi-layer structures; Gor kov equations; quasiclassical Green s function; Green s function on classical trajectories;

    Sammanfattning : This Thesis is concerned with the quasiclassical theory of meso-scopic superconductivity. The aim of the Thesis is to introduce the boundary conditions for a quasiclassical Green’s function on partially transparent interfaces in mesoscopic superconducting structures and to analyze the range of applicability of the quasiclassical theory. LÄS MER

  3. 2. Transport theory and finite element methods for mesoscopic superconducting devices

    Författare :Kevin Marc Seja; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; non-equilibrium superconductivity; finite element methods; unconventional superconductors; quasiclassical theory; transport theory;

    Sammanfattning : At low temperatures, electrons in a superconductor exhibit pairing correlations that result in a macroscopic, phase-coherent ground state. This leads to peculiar electromagnetic properties such as the flow of dissipationless charge currents and expelling of external magnetic fields. LÄS MER

  4. 3. Crystallization of the superconducting phase in unconventional superconductors

    Författare :Patric Holmvall; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; pattern formation; spontaneous symmetry breaking; Andreev bound states; mesoscopic superconductivity; phase crystals; thin superconducting films; phase transitions; non-local Ginzburg-Landau theory; time-reversal symmetry; flat bands; unconventional superconductivity; quasiclassical theory; translational symmetry; cuprates; inhomogeneous superconductivity;

    Sammanfattning : Superconductivity is a macroscopic quantum phenomenon, in the sense that a macroscopic number of electrons form a pair condensate, that occupies a single ground state. The electrons in this state are phase-coherent, breaking global U (1)-symmetry, and spatial variations of the phase imply superflows that usually cost kinetic energy, resulting in a uniform and rigid phase. LÄS MER

  5. 4. Mesoscopic thin film superconductors - A computational framework

    Författare :Mikael Håkansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Riccati equation; quasiclassical theory; simulation; GPU; time-reversal symmetry; CUDA; Eilenberger equation; coherence functions; Superconductivity; computational;

    Sammanfattning : Motivated by experiments on superconductors in the microscopic regime and the realization of small superconducting devices such as qubits, we initiate a computational project in the form of a numerical simulation package to model and predict the behavior of these type of systems. It is a multidisciplinary endeavor in that it employs theory, computational science, software design, and to some extent new visualization techniques. LÄS MER

  7. 5. Transport in mesoscopic superconducting devices

    Författare :Kevin Marc Seja; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; superconductivity; quasiclassical theory; mesoscopic physics; nonequilibrium superconductivity; Andreev bound states; superconducting spintronics;

    Sammanfattning : A field of growing interest within the last few decades is the study of superconductivity in mesoscopic-scale heterostructures. Mesoscopic refers to sizes between the atomic and macroscopic scales. LÄS MER