Search for dissertations about: "Critical phenomena phase transitions"

Showing result 1 - 5 of 11 swedish dissertations containing the words Critical phenomena phase transitions.

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

    Author : Hannes Meier; Mats Wallin; Asle Sudbø; KTH; []
    Keywords : 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;

    Abstract : 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. READ MORE

  4. 2. Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

    Author : Martina Ahlberg; Gabriella Andersson; Björgvin Hjörvarsson; Steve Bramwell; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  5. 3. Density-matrix renormalization-group analysis of quantum phase transitions in disordered spin chains

    Author : Laura Gabriela Urba; KTH; []
    Keywords : Quantum Phase Transitions; Spin Chains; Disordered Systems; Critical Phenomena;

    Abstract : .... READ MORE

  6. 4. 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

  7. 5. A Matter of Disorder : Monte Carlo Simulations of Phase Transitions in Strongly Disordered Systems

    Author : Marios Nikolaou; Mats Wallin; Asle Sudbø; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; phase transitions; disorder; Monte Carlo simulations; superconductivity; Statistical physics; Statistisk fysik;

    Abstract : Phase transitions and their critical scaling properties, especially in systems with disorder, are important both for our theoretical understanding of our environment, but also for their practical use in applications and materials in our everyday life. This thesis presents results from finite size scaling analysis of critical phenomena in systems with disorder, using high-precision Monte Carlo simulations and state of the art numerical methods. READ MORE