Sökning: "Cuprates"

Visar resultat 11 - 15 av 26 avhandlingar innehållade ordet Cuprates.

  1. 11. Hg Cuprate Superconductors Technological and Conceptual Tools

    Författare :Rafael Gatt; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mercury; high pressure; pulsed laser deposition; crystal growth; high temperature superconductors; cluster calculations; flat bands; thin oxide films; powder diffraction; structure refinement; phase transition; electronic structure; liquid phase epitaxy;

    Sammanfattning : This work concerns superconductivity in the cuprates. It touches some of the problems that this field displays. As a representing case, the Hg based cuprates are chosen. LÄS MER

  3. 12. Mechanistic Studies of Organocopper Chemistry by NMR Spectroscopy: Conjugate Additions to Alkynes and Alkenes

    Författare :Karolina Nilsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cyanocuprate; organocopper reagents; ynones; lithium dimethylcuprate; 13C and 15N NMR spectroscopy; pi-complexes; mechanism; enoates; 6Li; 1H-HOESY; ynoates; conjugate addition;

    Sammanfattning : This thesis focuses on the mechanisms of organocopper reactions, in particular the reactions with activated alkynes (ynoates and ynones). These reactions are of interest in the formation of new highly functionalized double bonds with control of the stereochemistry. LÄS MER

  4. 13. Reshaping the phase diagram of YBa2Cu3O7-δ through strain in ultrathin films and nanowires

    Författare :Eric Wahlberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; phase-slip; strange metal; High-Tc superconductors; thin-films; underdoped; nanowires; YBCO; charge density wave;

    Sammanfattning : This thesis aims at adding important pieces to the puzzle of understanding the physics of the High critical Temperature Superconductor (HTS) cuprates, where despite over 30 years of intense research many open questions remain. The HTS cuprates are characterized by an incredibly complex phase diagram with multiple intertwined local orders, such as charge density waves (CDW). LÄS MER

  5. 14. Role of charge and spin fluctuations and their interplay in solids : A Green’s function approach

    Författare :Tor Sjöstrand; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Green’s function; correlations; collective excitations; screened interaction; electric polarization; orbital and spin magnetization; magnon-phonon interaction; Fierz ambiguity; time-dependent exchange-correlation potential;

    Sammanfattning : Due to the large number of electrons, solid state physics boils down to many-body approximations in which only selected types of collective excitations are taken into account, guided by the emergent properties of the material under study. In this thesis, the collective excitations of primary interest are electronic charge and spin fluctuations(plasmons and magnons) and nuclear charge fluctuations (phonons). LÄS MER

  7. 15. Quantum Mechanical Studies of Electron Transport Processes Including Superconductivity

    Författare :Agris Klimkans; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum chemical calculations; ab initio; electronic;

    Sammanfattning : Processes of electron transfer, charge and spin localization, and electron pair transfer have been studied on the basis of the Marcus model and with the help of accurate quantum chemical calculations. A vibrational model, based on the corrections to the Born-Oppenheimerapproximation, which applies in the case of a vanishing barrier in the Marcus model, has been proposed. LÄS MER