Search for dissertations about: "Dirac theory"

Showing result 21 - 25 of 30 swedish dissertations containing the words Dirac theory.

  2. 21. Free Boundary Problems of Obstacle Type, a Numerical and Theoretical Study

    Author : Mahmoudreza Bazarganzadeh; Henrik Shahgholian; John King; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Partial differential equations; Numerical analysis; Free boundary problems; Mathematics; Matematik;

    Abstract : This thesis consists of five papers and it mainly addresses the theory and schemes to approximate the quadrature domains, QDs. The first deals with the uniqueness and some qualitative properties of the two QDs. The concept of two phase QDs, is more complicated than its one counterpart and consequently introduces significant and interesting open. READ MORE

  4. 22. Theoretical Investigations of Two-Dimensional Materials : Studies on Electronic, Magnetic, Mechanical, and Thermal Properties

    Author : Xin Chen; Biplab Sanyal; Susanne Mirbt; Kristian Sommer Thygsen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; 2D materials; DFT; Structure search; Functional materials; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Two-dimensional (2D) materials have been paid enormous attention since the first realization of graphene in 2004, in connection to high-speed flexible electronics, 2D magnetism, optoelectronics, and so on. Apart from graphene, many new 2D materials with special properties have been predicted and synthesized. READ MORE

  5. 23. Anomaly and Topology : On the axial anomaly, domain wall dynamics, and local topological markers in quantum matter

    Author : Julia D. Hannukainen; Jens H. Bardarson; Adolfo G. Grushin; Teemu Ojanen; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; chiral anomaly; axial anomaly; topological phases of matter; Weyl semimetals; magnetic domain walls; local topological markers;

    Abstract : Chiral anomalies and topological phases of matter form the basis of the research presented in this dissertation. The chiral anomaly is considered both in the context of magnetic Weyl semimetals and in the context of non-Hermitian Dirac actions. READ MORE

  6. 24. Evaluation of NMR Knight shifts in metallic nanoparticles and topological matter

    Author : Wassilios Papawassiliou; Andrew Pell; Niklas Hedin; Ulla Gro Nielsen; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; solid-state NMR; Knight shifts; metallic systems; topological matter; nanoparticles; DFT calculations; Physical Chemistry; fysikalisk kemi;

    Abstract : Elucidating the surface electron states of transition metal compounds is of primary importance in main heterogeneous catalytic processes, such as the hydrogen and oxygen evolution reactions.  Key property in all these processes is the position of the energy of the d-band center relative to the Fermi-level of the catalyst; it must be shifted close to the Fermi level to achieve balance between adsorption and desorption of the catalyst and the adsorbate. READ MORE

  7. 25. New Approaches to Large-Scale Electronic Structure Calculations

    Author : Francesco Aquilante; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; orbital localization; electron correlation; analytic gradients; Cholesky decomposition; density fitting; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : Recent years have witnessed a growing interest of the scientific community for the use of ab initio and density functional theory methods in theoretical studies of molecules containing many atoms. However, the `scaling wall' of some of the most accurate of such methods is often an obstacle for their applicability to systems of real-life interest, e. READ MORE