Search for dissertations about: "Dirac"

Showing result 1 - 5 of 51 swedish dissertations containing the word Dirac.

2. 1. Interacting Dirac Matter

   Author : Saikat Banerjee; Alexander V. Balatsky; Jens Paaske; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dirac; superconductor; magnon; interaction; Fermi liquid theory; renormalization; Fysik; Physics;

   Abstract : The discovery of graphene in 2004 has led to a surge of activities focused on the theoretical and experimental studies of materials hosting linearly dispersive quasiparticles during the last decade. Rapid expansion in the list of materials having similar properties to graphene has led to the emergence of a new class of materials known as the Dirac materials. READ MORE

4. 2. Resonances of Dirac Operators

   Author : Jimmy Kungsman; Wolfgang Staubach; Roman Schubert; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Semiclassical analysis; Dirac operator; resonances; Poisson trace formula; scattering theory; complex absorbing potential; pseudodifferential operator; Mathematics; Matematik;

   Abstract : This thesis consists of a summary of four papers dealing with resonances of Dirac operators on Euclidean 3-space. In Paper I we show that the Complex Absorbing Potential (CAP) method is valid in the semiclassical limit for resonances sufficiently close to the real line if the potential is smooth and compactly supported. READ MORE

5. 3. The Dirac Equation: Numerical and Asymptotic Analysis

   Author : Hasan Almanasreh; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Dirac operator; eigenvalue problem; finite element method; spurious eigenvalues; Petrov-Galerkin; cubic Hermite basis functions; stability parameter; meshfree method; $hp$-cloud; intrinsic enrichment; G-convergence; $ Gamma$-convergence; scattering theory; identification; wave operator; stationary approach; Dirac operator;

   Abstract : The thesis consists of three parts, although each part belongs to a specific subject area in mathematics, they are considered as subfields of the perturbation theory. The main objective of the presented work is the study of the Dirac operator; the first part concerns the treatment of the spurious eigenvalues in the computation of the discrete spectrum. READ MORE

6. 4. Topological Phase Transitions in Magnetic Nanostructures of Dirac Materials

   Author : Nezhat Pournaghavi; Carlo M. Canali; Michael Flatté; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Topological insulators; Magnetic materials; Quantum anomalous Hall effect; Topological magneto electric effect; Dirac semimetals; Weyl semimetals; Condensed Matter Physics; Kondenserade materians fysik;

   Abstract : Over the past two decades, the discovery of topological Dirac materials, such as topological insulators and semimetals, has defined a new paradigm in condensed matter physics and established new platforms for realizing spin electronic devices and quantum computing. The novel quantum properties of these materials, which are mainly due to the presence of strong spin-orbit coupling, are invariant under topological transformations, making them more resilient to structural disorder, electromagnetic and thermal fluctuations in comparison to the conventional silicon-based materials. READ MORE

7. 5. The Dirac Operator; From Numerics to the Theory of G-convergence

   Author : Hasan Almanasreh; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Dirac operator; spuriousity; cubic Hermitian; stability parameter; G-convergence; ¡-convergence; spectral measure; quadratic form; stability parameter;

   Abstract : We consider two main issues concerning the Dirac operator, the first is widely known as the appearance of spurious eigenvalues within the spectrum. The second is the study of the asymptotic behavior of the eigenvalues for a family of Dirac operators with oscillatory potential added to the Coulomb-Dirac Hamiltonian. READ MORE