Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 32 for “"microscopic theory"”.
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A microscopic theory of tunneling
"A microscopic theory of impurity-assisted tunneling is constructed in which the current-carrying (extended) eigenstates of the average one electron potential in a tunnel junction are utilized as the basis functions which are mixed by the Hamiltonian associated with the presence of a static or …
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Fission dynamics in a microscopic theory
… of the time-dependent density functional theory (TDDFT) to investigate the fission dynamics of atomic nucleus, which is still one of the most complicated problem in nuclear physics and a full microscopic interpretation is still missing. The establishment of the time-dependent superfluid …
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Microscopic Theory of the Knight Shift
… is the beginning of the development of a microscopic theory of the Knight shift. The Knight shift experiment has been used in superconductivity research throughout history, however, a complete understanding of the Knight shift in conventional as well as unconventional superconductors does …
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On the microscopic theory of liquid ⁴He
"A microscopic description of the ground state and elementary excitations of liquid 4He is presented. The variational theory is used in conjunction with a perturbative scheme called correlated basis perturbation theory. The hypernetted-chain technique is used to calculate the various matrix …
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Microscopic theory for dynamics in entangled polymer nanocomposites
New microscopic theories for describing dynamics in polymer nanocomposites are developed and applied. The problem is addressed from two distinct perspectives and using two different theoretical approaches. The first half of this dissertation studies the long-time and intermediate-time dynamics of …
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Microscopic Theory of Linear Response in Amorphous Materials
… Tg. Moving to the mechanical aspect, the theory of nonaffine lattice dynamics is able to describe the various relaxation processes in the linear viscoelastic response of metallic glasses. In particular, to understand universal properties of relaxation, the VDOS obtained in simulations, or …
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MICROSCOPIC THEORY OF INFINITE NUCLEAR MATTER AND NON-EMPIRICAL ENERGY FUNCTIONALS
Nuclear density functional theory (DFT) and ab initio theory are complementary approaches to nuclear structure. DFT can be applied to the whole nuclear chart, but relies on empirical energy density functionals (EDFs). As a consequence, predictions in regions where experimental data are lacking, …
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Physics-based models of hysteresis in multiphase flow in porous media
… on pore-scale probabilistic events to derive a theory of hysteresis in multiphase flow in porous media. In particular, we define the pore-space accessivity to contrast the serial and parallel arrangement of different-radius pore slices, and the radius-resolved saturations to detail the …
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Computational Modeling of Superconductivity from the Set of Time-Dependent Ginzburg-Landau Equations for Advancements in Theory and Applications
… the dynamics of superconductors in various theory revealing states and practical purposes. A review of the history and phenomenon of superconductivity, including modern applications, is introduced. The Josephson effect and associated Josephson junction are discussed for comparison to our …
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Stochastic congruence equations for spacetime fluctuations
… arises as the thermodynamic limit of some microscopic theory. As such, one would expect the macroscopic variables such as the curvature tensors to fluctuate about their mean. This thesis presents a method for analyzing the effects of curvature fluctuations on spacetime thermodynamics. This …
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Phonon-quasiparticle interactions in dilute solutions of He3 in superfluid He4
… between quasiparticles are discussed from the microscopic theory. Much of the previous semiphenomonological theory concerning these quantities is justified. The properties of a dilute gas model for dilute solutions are worked out to first order in the gas parameter; the results provide an …
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Determing the Properties of Dense Matter: Superconductivity, Bulk Viscosity, and Light Reflection in Compact Stars
… in neutron star cores. We derive an effective theory of Cooper pair quasiparticles from a microscopic theory of nucleons, and calculate the coupling strengths between quasiparticles. We then calculate the structure of magnetic flux tubes, taking into consideration interactions between neutron …
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Quantum dynamics in condensed phases : charge carrier mobility, decoherence, and excitation energy transfer
… in organic molecular crystals, and develop a microscopic theory that describes both the coherent band-like and incoherent hopping transport observed in organic crystals. We investigate the structures of polaron states using a variational scheme, and calculate both band-like and hopping …
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Statistical mechanics of the amorphous solid state of randomly crosslinked macromolecules
… solid state occurs. In this thesis a semi-microscopic theory of the vulcanization transition is developed, and the emergent amorphous solid state is studied in detail, close to the transition. In the first part of this work a derivation is presented of the free energy functional for a …
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An absolute measurement of the photodisintegration of Helium-4
… the simplest, holds the promise of perfecting a microscopic theory of nuclear dynamics, in which nuclear structure and reactions are understood in terms of fundamental particle interactions. The measurement was performed with a tagged-photon beam, using a large solid-angle charged particle …
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Visualizing Cooper Pair Formation on the Atomic Scale in High Temperature Superconductors
In the quest for a microscopic theory for the superconductivity in cuprates, one hotly debated issue is the temperature at which Cooper pairs first form. Do pairs form at the critical temperature Tc or do they form at higher temperatures lacking phase rigidity? To answer the question, we have …
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A Statistical Theory of Fragmentations of Nuclei by Light Projectiles and Macroscopic Theory to Incorporate Resonances in the Mean Field
… containing one- and two-body operators, a microscopic theory has been developed to incorporate resonances in the mean field for the scattering theory. It indicates that the structure of the S-matrix obtained differs from some of the empirical ones applied in an ad hoc way to describe …
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Harmonic and Supercontinuum Generation in Zinc-Blende Materials
… we explore the possibility of employing fully microscopic theory. A semiconductor Bloch equations based approach is presented, taking into account contributions from the entire 3D Brillouin zone, and the connection between symmetry of the medium and the generation of high harmonics is …
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Investigation of superconducting order parameters in heavy-fermion and low-dimensional metallic systems under pressure
… in 1911, prior to the development of the quantum theory of matter, superconductivity was defying a microscopic theory for more than four decades until the BCS theory was formulated in 1957 by J. Bardeen, L. N. Cooper and J. R. Schrieffer. Superconductivity of most of the simple metals or metallic …
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