Sökning: "Quasiparticle."

Visar resultat 21 - 25 av 40 avhandlingar innehållade ordet Quasiparticle..

  1. 21. Modeling mesoscopic unconventional superconductors

    Författare :Patric Holmvall; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phase transitions; Andreev bound states; quasiclassical theory; mesoscopic thin-films; spontaneous symmetry breaking; time-reversal symmetry; Unconventional superconductivity; translational symmetry;

    Sammanfattning : High-temperature superconducting materials are often experimentally realized as thin films that can be patterned into devices operating in the mesoscopic regime. On this length scale, various finite-size and surface effects heavily influence the nature of the superconducting state, and can induce new ground states with spontaneously broken symmetries. LÄS MER

  3. 22. Transport Properties of Superconducting d-wave junctions

    Författare :Tomas Löfwander; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : At surfaces and interfaces of d-wave superconductors, quasiparticle bound states with zero energy, midgap states (MGS), are necessarily formed as a consequence of the sign change of the d-wave order parameter upon 90° rotation. The MGS can never exist at s-wave superconductor surfaces and are therefore true fingerprints of unconventional superconductivity. LÄS MER

  4. 23. High-frequency phenomena in small Bi2Sr2CaCu2O8+x intrinsic Josephson junctions

    Författare :Holger Motzkau; Vladimir M. Krasnov; Reinhold Kleiner; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductivity; Bi-2212; cuprates; intrinsic Josephson junctions; intrinsic tunneling; fluxons; flux-flow oscillator; THz-emission; cavity resonances; polaritons; electrical doping; micro nano-fabrication; fysik; Physics;

    Sammanfattning : In this thesis, the tunneling between individual atomic layers in structures of Bi2Sr2CaCu2O8+x based high-temperature superconductors are experimentally studied employing the intrinsic Josephson effect. A special attention is paid to the fabrication of small mesa structures using micro and nanofabrication techniques. LÄS MER

  5. 24. Electromechanical Phenomena in Superconducting and Normal Nanostructures

    Författare :Milton Eduardo Peña-Aza; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanoelectromechanical systems; nanoelectromechanical Josephson junctions; metallic carbon nanotubes; ground-state cooling; chaos;

    Sammanfattning : This thesis summarizes a series of theoretical studies on the electromechanical properties of nanostructures made of superconducting and/or metallic elements. The first part of the work is devoted to the analysis of the interactions between the electronic and mechanical degrees of freedom in suspended nanowires. LÄS MER

  7. 25. In-Beam Spectroscopy of Extremely Neutron Deficient Nuclei 110Xe, 163Ta, 169Ir and 172Hg

    Författare :Mikael Sandzelius; Bo Cedervall; David Cullen; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Sammanfattning : This thesis describes new results obtained from experimental studies of the extremely neutron-deficient isotopes 110Xe, 163Ta, 169Ir, and 172Hg, close to the proton drip-line. The experiments used state-of-the-art equipment for nuclear spectroscopy where a large high resolution Germanium-detector array was coupled to a high-transmission recoil separator. LÄS MER