Sökning: "NATURAL SCIENCES Physics Condensed matter physics Critical phenomena phase transitions"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden NATURAL SCIENCES Physics Condensed matter physics Critical phenomena phase transitions.

  1. 1. Phase transitions in novel superfluids and systems with correlated disorder

    Författare :Hannes Meier; Mats Wallin; Asle Sudbø; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; condensed matter physics; phase transitions; critical phenomena; spin models; quantum phase transitions; quantum fluids; superfluidity; superconductivity; disordered systems; Bose glass; dirty bosons; vortex pinning; statistical mechanics; Monte Carlo simulation; Wolff algorithm; classical worm algorithm; Wang-Landau algorithm; Fysik; Physics;

    Sammanfattning : Condensed matter systems undergoing phase transitions rarely allow exact solutions. The presence of disorder renders the situation  even worse but collective Monte Carlo methods and parallel algorithms allow numerical descriptions. LÄS MER

  3. 2. Quantum Holonomy for Many-Body Systems and Quantum Computation

    Författare :Vahid Azimi Mousolou; Erik Sjöqvist; Rosario Fazio; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum holonomy; geometric phase; quantum correlations; quantum phase transitions; quantum computation; Natural Science; Naturvetenskap; Physics; Fysik;

    Sammanfattning : The research of this Ph. D. thesis is in the field of Quantum Computation and Quantum Information. A key problem in this field is the fragile nature of quantum states. LÄS MER

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

    Författare :Patric Holmvall; Chalmers tekniska högskola; []
    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. 4. Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

    Författare :Martina Ahlberg; Gabriella Andersson; Björgvin Hjörvarsson; Steve Bramwell; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phase transitions; critical behavior; 2D XY model; MOKE; magnetic thin films and superlattices; amorphous multilayers; magnetic proximity effects; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The continuous phase transition in thin magnetic films and superlattices has been studied using the magneto-optical Kerr effect (MOKE) and polarized neutron scattering (PNR).  It has been shown that the critical behavior of amorphous thin films belonging to the 2D XY universality class can be described within the same theory as crystalline sample. LÄS MER

  7. 5. First Principles Calculations of Electron Transport and Structural Damage by Intense Irradiation

    Författare :Carlos Ortiz; Olle Eriksson; Mattias Klintenberg; Richard A. London; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Condense matter theory; electronic structure; quasiparticles; GW theory; molecular dynamics; Boltzmann transport; electron transport; impact ionization; structural damage; dielectric response; structural biology; radiation detectors; scintillators; positron emission tommography; Electronic structure; Elektronstruktur; Semiconductor physics; Halvledarfysik; Biological physics; Biologisk fysik; Critical phenomena phase transitions ; Kritiska fenomen fasövergångar ; Functional materials; Funktionella material; Materiefysik; Physics of Matter;

    Sammanfattning : First principle electronic structure theory is used to describe the effect of crystal binding on radiation detectors, electron transport properties, and structural damage induced by intense irradiation. A large database containing general electronic structure results to which data mining algorithms can be applied in the search for new functional materials, a case study is presented for scintillator detector materials. LÄS MER