Search for dissertations about: "FIELD REVERSAL"

Showing result 11 - 15 of 47 swedish dissertations containing the words FIELD REVERSAL.

  2. 11. Modeling mesoscopic unconventional superconductors

    Author : Patric Holmvall; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : 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. READ MORE

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

    Author : Patric Holmvall; Chalmers tekniska högskola; []
    Keywords : 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;

    Abstract : 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. READ MORE

  5. 13. Directional Decomposition in Anisotropic Heterogeneous Media for Acoustic and Electromagnetic Fields

    Author : B. Lars G. Jonsson; KTH; []
    Keywords : directional wave-field decomposition; wave splitting; spectral reduction; aourstic anisotropy; electromagnetic anisotropy; generalized eigenvalue problem;

    Abstract : Directional wave-field decomposition for heterogeneousanisotropic media with in-stantaneous response is establishedfor both the acoustic and the electromagnetic equations.We derive a sufficient condition for ellipticity of thesystem's matrix in the Laplace domain and show that theconstruction of the splitting matrix via a Dunford-Taylorintegral over the resolvent of the non-compact, non-normalsystem's matrix is well de ned. READ MORE

  6. 14. Magnetic Bicrystal Junctions - a Study of Half-Metallic Manganite Grain Boundaries

    Author : Robert Gunnarsson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : This thesis presents studies on magnetic bicrystal junctions. In these, films on either side of the junction are structurally and magnetically misoriented. This type of device enables us to study junction magnetoresistance and spin polarized charge transport between ferromagnets with well defined directions of magnetization. READ MORE

  7. 15. On Some Properties and Applications of Patterned Ferromagnetic Thin Films

    Author : Pierre E. Roy; Peter Svedlindh; Per Nordblad; Jeffrey McCord; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; micromagnetics; vortex; spin dynamics; domains; MFM; microwave; patterned; permalloy; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Abstract : A microwave reflection method has been used to measure the spin excitations corresponding to the translational mode of magnetic vortices in samples containing either one or two vortices. Experimental findings are complemented by micromagnetic simulations. One-vortex systems are investigated in micron-sized circular and elliptical cylinders. READ MORE