Springer International Publishing, 2017 — 252p. — (Lecture Notes in Physics 927) — ISBN: 978-3-319-39833-4 (eBook), 978-3-319-39831-0 (Softcover).In this book the coherent quantum transport of electrons through two-dimensional mesoscopic structures is explored in dependence of the interplay between the confining geometry and the impact of applied magnetic fields, aiming at conductance controllability. After a top-down, insightful presentation of the elements of mesoscopic devices and transport theory, a computational technique which treats multiterminal structures of arbitrary geometry and topology is developed. The method relies on the modular assembly of the electronic propagators of subsystems which are inter- or intra-connected providing large flexibility in system setups combined with high computational efficiency. Conductance control is first demonstrated for elongated quantum billiards and arrays thereof where a weak magnetic field tunes the current by phase modulation of interfering lead-coupled states geometrically separated from confined states. Soft-wall potentials are then employed for efficient and robust conductance switching by isolating energy persistent, collimated or magnetically deflected electron paths from Fano resonances. In a multiterminal configuration, the guiding and focusing property of curved boundary sections enables magnetically controlled directional transport with input electron waves flowing exclusively to selected outputs. Together with a comprehensive analysis of characteristic transport features and spatial distributions of scattering states, the results demonstrate the geometrically assisted design of magnetoconductance control elements in the linear response regime.Contents: Introduction Electrons in Low-Dimensional Mesoscopic Systems Coherent Electronic Transport: Landauer-Büttiker Formalism Stationary Scattering in Planar Confining Geometries Computational Quantum Transport in Multiterminal and Multiply Connected Structures Magnetoconductance Switching Current Control in Soft-Wall Electron Billiards: Energy-Persistent Scattering in the Deep Quantum Regime Directional Magnetotransport Control in Multiterminal Focusing Quantum Billiards Summary, Conclusions, and Perspectives
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