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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 13 of 13 for “"weak localization"”.
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Quantum evolution: The case of weak localization for a 3D alloy-type Anderson model and application to Hamiltonian based quantum computation
… from a microscopic point of view. Anderson localization, named after physicist P. W. Anderson, states that disorder in a crystal can cause non-spreading of wave packets, which is one possible mechanism (at single electron level) to explain metalinsulator transitions. The theory of quantum …
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Transport studies on CVD-grown graphene
… mobilities. We also examine what we find to be weak signatures of Shubnikov-de Haas oscillations in magnetic field sweeps. Finally, we study magneto-resistance effects at low fields, and find that the sample exhibits weak-localization effects.
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Fabrication and Transport Properties of Silicon Nanoelectronic Devices
… display the low-temperature phenomena of weak localization and one-dimensional conduction. Long-term applications of such nanowires and derivative devices include alternatives to conventional CMOS transistors and very sensitive charge and/or spin-detection devices. In addition, focused ion …
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Quantum-coherent transport in low-dimensional mesoscopic structures and thin films
… phase coherence lengths were extracted from antilocalization signals. Antilocalization measurements provide a sensitive mean of probing the quantum mechanical correction to electronic transport. The phase coherence lengths increased as the wire length increased, due to reduction of the …
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Silicon Nanoelectronic Devices Fabricated by Ultra-High Vacuum, Scanning Tunneling Microscope Nanolithography
… magnetoconductance: a characteristic of a weakly localized electron gas. The 2D electron density (∼ 1 x 1014 cm-2) is significantly higher than modulation-doped structures. This allows the lateral patterning of low-dimensional devices without the formation of undesirable carrier …
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Effects of energetic irradiation on materials and devices based on graphene and topological insulators
… for relating Raman peak intensities and weak localization features to each other and to an average disorder length in graphene, <em>L<sub>D</sub></em>. ^ We then integrate gate-effect measurements into the Raman spectroscopy study to fully explore the relationships between carrier …
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Coherent Transport of Matter Waves in Disordered Optical Potentials
… has evoked new interest for the disorder-induced localization of ultra-cold atoms. This work studies the transport properties of matter waves in disordered optical potentials, which are also known as speckle potentials. The effect of correlated disorder on localization is first studied numerically …
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Numerical and Laboratory Studies of Ultrasonic Anderson Localization
A numerical study of Anderson localization in two dimensions and a laboratory study of weak localization in three dimensions are presented. The two-dimensional study was performed by mathematically modelling a system of masses connected to a rigid base by springs of random stiffness. The masses …
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Spin-Orbit Coupling in SrTiO3/Si Thin Films at High Carrier Concentration
… carrier concentration (≤ 10¹⁴, cmˉ²) which shows Weak- localization effect. As the carrier concentration increases ( (1 − 2) × 10¹⁴, cmˉ²), we see WAL effect which occur due to spin -orbit coupling. The thesis describes the results on my thesis research. I investigate the effect of spin-orbit …
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Investigating electron transport in chemical vapor deposition graphene nanostructures
… heterostructure and a special transition from weak localization (WL) to weak antilocalization (WAL) is found around a certain carrier concentration due to surface roughness induced patches. This result provides insight into fabrication and operation of scalable graphene spintronic devices. …
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Experimental Measurements by Antilocalization of the Interactions between Two-Dimensional Electron Systems and Magnetic Surface Species
Low-temperature weak-localization (WL) and antilocalization (AL) magnetotransport measurements are sensitive to electron interference, and thus can be used as a probe of quantum states. The spin-dependent interactions between controllable surface magnetism and itinerant electrons in a non-magnetic …
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Mesoscopic quantum interference experiments in InGaAs and GaAs two-dimensional systems
… has strong spin-orbit interaction (SOI). Antilocalization in a Hall bar geometry was analyzed by the 2D Hikami-Larkin-Nagaoka (HLN) theory to obtain the spin coherence time and phase coherence time. The 2D hole systems we studied have low density and high mobility, quite different from the 2D …
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Growth and characterization of epitaxial graphene films by Molecular Beam Epitaxy
Growing macroscopic graphene films with the aim of making graphene commerically viable is being researched a lot recently. Although graphene isolated by exfoliation of Highly Oriented Pyrolytic Graphite (HOPG) crystals has been in place for sometime now, its micro sample size has triggered the …