Sökning: "d-wave symmetry"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden d-wave symmetry.

  1. 1. Symmetry, Disorder and the Josephson Effect in d-Wave Superconductors

    Författare :Fabian Wenger; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; density of states; Josephson effect; high-Tc; symmetry; cuprate; disorder; d-wave; superconductor; order parameter;

    Sammanfattning : This thesis focuses on aspects of symmetry, disorder and the Josephson effect in d-wave superconductors which are generically characterized by sign changes of the gap function .DELTA.k in certain directions with respect to the underlying crystal lattice. LÄS MER

  3. 2. d-wave Josephson Junctions

    Författare :Tobias Lindström; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson junctions; high-temperature superconductivity; Andreev states;

    Sammanfattning : The properties of d-wave YBCO Josephson junctions and dc-SQUIDs with high misorientation angles have beenstudied experimentally .The predominant d-wave symmetry of the pairing wavefunction in high-Tc superconductors has, to a large extent, beena hinderance in applications, but it also makes it possible to fabricate devices with novel properties that may be suitablefor applications in the quantum regime; one particulary interesting property is a strong second harmonic component in the current-phase relation ofjunctions with the electrodes oriented in a node-lobe arrangement; so-called 0-45 junctions. LÄS MER

  4. 3. 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

  5. 4. Quantum dynamics of spin active and d-wave Josephson junctions

    Författare :Jens Harro Michelsen; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Josephson effect; macroscopic quantum tunneling; high-temperature superconducvity; superconducting junctions; spin-active junctions; nonequilibrium superconductivity; Andreev bound states;

    Sammanfattning : Conventional tunnel Josephson junctions form the basic building blocks of superconducting electronics. Their operation is based on comparatively simple dynamics where the superconducting phases across the junctions is the only dynamical degree of freedom. LÄS MER

  7. 5. Multiple Andreev Reflection - a Microscopic Theory of ac Josephson Effect in Mesoscopic Junctions

    Författare :Göran Johansson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-Tc superconductors; d-wave symmetry; superconducting junctions; resonant tunneling; ac Josephson effect; mesoscopic superconductivity;

    Sammanfattning : The mechanism of multiple Andreev reflection (MAR) is a microscopic theory for electron transport in voltage biased superconducting junctions, i.e. the ac Josephson effect. In this thesis we propose a new approach for calculating the dc current from MAR. LÄS MER