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Showing 1 to 20 of 276 for “"dirac"”.
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Quantum oscillations in Dirac semimetals
Dirac semimetals have recently gained interest due to their unique experimental signatures many of which can be explained by the topologically non-trivial band structure in these materials. Among the many candidates, the tellurides NbTe₄, TaPtTe₅ and TaNiTe₅ appear to provide a promising platform …
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Spectral asymptotics for coupled Dirac operators
… asymptotic spectral flow for a family of coupled Dirac operators. We prove that the leading order term in the spectral flow on an n dimensional manifold is of order r n+1/2 followed by a remainder of O(r n/2). We perform computations of spectral flow on the sphere which show that O(r n-1/2) is the …
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Dirac operators and monopoles with singularities
… of the thesis, we prove an index theorem for Dirac operators of conic singularities with codimension 2. One immediate corollary is the generalized Rohklin congruence formula. The eta function for a twisted spin Dirac operator on a circle bundle over a even dimensional spin manifold is also …
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The evolution equations for Dirac-harmonic Maps
This thesis investigates the gradient flow of Dirac-harmonic maps. Dirac-harmonic maps are critical points of an energy functional that is motivated from supersymmetric field theories. The critical points of this energy functional couple the equation for harmonic maps with spinor fields. At …
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Global dynamics of Schrodinger and Dirac equations
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2020-08-01
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A direct search for Dirac magnetic monopoles
Magnetic monopoles are highly ionizing and curve in the direction of the magnetic field. A new dedicated magnetic monopole trigger at CDF, which requires large light pulses in the scintillators of the time-of-flight system, remains highly efficient to monopoles while consuming a tiny fraction of …
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Relativistic dynamics and Dirac particles in graphene
… fields and use the Lorentz symmetry of the Dirac equation to solve for magnetoconductance. Next, we proceed to study monolayer quasiparticles in a deconfining potential and a magnetic field. The twodimensional nature of graphene allows us to study competition between the two external fields. …
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Manipulation and analysis of topological properties in hybrid Dirac materials [Manipolazione ed analisi delle proprietà topologiche dei materiali di Dirac]
… sulla manipolazione controllata dei materiali di Dirac. In particolare, vengono studiati due tipi di sistemi: i semimetalli a linea nodale ingegnerizzati tramite campi Floquet e le eterostrutture superconduttive a base di grafene. Nella prima parte della tesi, studiamo gli stati di interfaccia che …
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Geometric algebras in physics: Eigenspinors and Dirac theory
… that is closely related to the standard Dirac equation. The algebra of physical space, APS, gives clear insight into the quantum/classical interface. Here, APS is compared to other formulations of relativistic quantum theory, especially the Dirac equation. These formulations are shown to …
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Self-adjoint extensions to the Dirac Coulomb Hamiltonian
The Dirac equation is the relativistic generalization of the Schrödinger equation for spin 1/2 particles. It is written in the form -ihc -ihac OXIa+t' Omc 29 = ih-o (1.1) where V) is a four component Dirac spinor and the coefficients a and # are 4 x 4 matrices. Like the Schrödinger equation, the …
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On the parallels between the Maxwell and Dirac equations
… deeply the similarity between the Maxwell and Dirac equations. We reformulate the Dirac equation in an \emph{exact} form of the Maxwell equations, which we refer to as the ``electronic Maxwell equations.'' In this formulation, the standard free Maxwell equations emerge as a special case …
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Growth, Structural and Electrical Characterization of Topological Dirac Materials
… fabricate and measure devices on topological Dirac materials, with the hope to experimentally distinguish the bulk from the surface states and also exploit their exotic properties arising from opening of the bulk band gap by intentional magnetic doping. Samples consisted of thin films of …
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Dirac R-matrix scattering calculations in support of plasma diagnostics
… are carried out using the relativistic Dirac R-matrix (DARC) and the semi-relativistic Breit-Pauli (BP) R-matrix codes. The results from these calculations, along with the atomic structure data, are incorporated into collisional-radiative model programs. These collisional-radiative …
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The bound states of Dirac equation with a scalar potential
"We study the bound states of the 1+1 dimensional Dirac equation with a scalar potential, which can also be interpreted as a position dependent ""mass'', analytically as well as numerically. We derive a Prüfer-like representation for the Dirac equation, which can be used to derive a condition for …
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Unique continuation theorems for the Dirac operator and the Laplace operator
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 1989.
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Results on the number of zero modes of the Weyl-Dirac operator
… magnetic potential A one can define the Weyl-Dirac operator σ·(−i∇−A) on R 3 . An L 2 eigenfunction of σ · (−i∇ − A) corresponding to 0 is called a zero mode. In this thesis we will be concerned with the zero mode problem for the WeylDirac operator and some related problems. The main results …
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Spectral Theory of the Atomic Dirac Operator in the No-Pair Formalism
… einer unitaeren Transformation wird der Coulomb-Dirac-Operator eines Ions in einen pseudorelativistischen Operator uebergefuehrt, der zu beliebiger Ordnung n in der Potentialstaerke block-diagonal ist bezueglich der Projektionen auf den positiven bzw. negativen Spektralraum des freien …
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Partial-Wave Analysis of Elastic-Scattering and Inelastic-Scattering of Dirac Particles
Made available in DSpace on 2014-12-10T20:13:39Z (GMT). No. of bitstreams: 1 7317327.pdf: 3893048 bytes, checksum: 5c2a16f339cc0875cb08ba8e4f9728f5 (MD5) Previous issue date: 1972
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