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 9 of 9 for “"Itinerant electrons"”.
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Wonderland of frustration: Magnetic moments and itinerant electrons on the pyrochlore lattice
… magnet deep in the Mott regime. The presence of itinerant carriers in large-U Hubbard models near half-filling is known to influence the spin correlations in the system, with Nagaoka’s theorem being a notable example. Nagaoka’s theorem is, however, restricted to bipartite lattices, and …
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Orbital order in iron-based superconductors
… this orbital order in the framework of the local-itinerant dichotomy. First, due to the spatial anisotropy of the occupied orbitals that form the local moments, the magnetic exchange constants acquire dramatically different values along the two in-plane directions. Second, the itinerant electrons …
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Power-law liquid in high-temperature superconductors
… high-$T_{c}$ superconductors, we study the local-itinerant dichotomy in iron pnictides. We show that an interplay between localized moments and itinerant electrons is needed to reproduce the spin excitations observed in inelastic neutron scattering experiments. These results further our …
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Aspects of Moiré Quantum Matter
… We also show that a class of models comprising itinerant electrons strongly coupled to skyrmion-like magnetic textures, closely connected with moiré transition metal dichalcogenides in which the fractional quantum anomalous Hall effect was observed, can host flat Chern bands, emergent Landau …
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Quantum Electronic Effects in Ultrathin Metal Films on Semiconductors
… arise due to quantum confinement of a metal's itinerant electrons to an ultrathin film and variations in the surface energy (relative stability) of such films as a function of thickness. These effects are first examined from a theoretical viewpoint, where models based upon a free-electron gas …
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Magnetic and superconducting quantum critical behavior of itinerant electronic systems
"Quantum phase transitions occur at zero temperature as a function of some non-thermal parameter, e.g., pressure or chemical composition. In addition to being of fundamental interest, quantum phase transitions are important because they are believed to underlie a number of interesting low …
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Magnetoconductance and Dynamic Phenomena in Single-Electron Transistors
<p>The quantum mechanical nature of electrons at very low temperatures has posed interesting results in the resistivity of metals over the last century. When the temperature nears absolute zero, the resistivity due to electron-electron interactions and electron-phonon interactions become very small …
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Local Magnetism in Strongly Correlated Electron Systems with Orbital Degrees of Freedom
… on the sub-class of these materials where electrons appear to be localized by interactions, and magnetic ions have well measured magnetic moments. This suggests that we can capture the low-energy physics of the material by employing a minimal model featuring localized spins which interact …
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Experimental Measurements by Antilocalization of the Interactions between Two-Dimensional Electron Systems and Magnetic Surface Species
… between controllable surface magnetism and itinerant electrons in a non-magnetic host provide insight for spin-based technologies, magnetic data storage and quantum information processing. This dissertation studies two different host systems, an In$_{0.53}$Ga$_{0.47}$As quantum well at a …