Sökning: "symmetry breaking"

Visar resultat 1 - 5 av 46 avhandlingar innehållade orden symmetry breaking.

  1. 1. Symmetry Breaking Ordering Constraints

    Detta är en avhandling från Uppsala : Data- och systemvetenskap

    Författare :Zeynep Kiziltan; Andreas Hamfelt; Toby Walsh; Pedro Meseguer; [2004]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Datavetenskap; Constraint satisfaction; constraint programming; modelling; symmetry breaking; global constraints; Datavetenskap; TECHNOLOGY Information technology Computer science; TEKNIKVETENSKAP Informationsteknik Datavetenskap;

    Sammanfattning : Many problems in business, industry, and academia can be modelled as constraint programs consisting of matrices of decision variables. Such “matrix models” often have symmetry. In particular, they often have row and column symmetry as the rows and columns can freely be permuted without affecting the satisfiability of assignments. LÄS MER

  2. 2. Breaking the symmetry : spin splitting of hole subbands in strained quantum wells

    Detta är en avhandling från Fysiska institutionen

    Författare :Oskar Mauritz; [1997]
    Nyckelord :;

    Sammanfattning : Properties of the subband structure and related propertiesof quantum wells (QWs) are investigated, within the frameworkof the multi-band envelope function method. The subbands of aQW are replaced by discrete Landau levels when a magnetic fieldis applied perpendicular to the plane of the well. LÄS MER

  3. 3. Circle maps with symmetry-breaking perturbations

    Detta är en avhandling från Fysiska institutionen

    Författare :Anders B. Eriksson; [1991]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; circle map; subharmonic perturbation; chaos transitions; renormalization group theory; quasiperiodicity;

    Sammanfattning : .... LÄS MER

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

    Detta är en avhandling från Gothenburg : Chalmers tekniska högskola

    Författare :Patric Holmvall; [2019]
    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. 5. Modeling mesoscopic unconventional superconductors

    Detta är en avhandling från Gothenburg : Chalmers tekniska högskola

    Författare :Patric Holmvall; [2017]
    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