Computational quantum transport in mesoscopic electronic waveguides

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Quantum transport in mesoscopic systems of high numerical complexity resulting in a high variability of transport properties will be investigated. Specifically we study the impact of external magnetic fields on the transmission of complex electron waveguides. The latter are formed by finite arrays of, in general different, quantum dots possessing tunable spectra. The geometry of the dots, the positioning of the leads and hi particular the application of magnetic fields, either homogeneous or inhomogeneous, influence the electron dynamics and consequently the transport properties of the guide. Varying and optimizing the geometry of the arrays, thermal broadening due to finite temperature, incoherent contributions to the currents and spin-dependent transport are relevant aspects to be studied. The computational scheme is based on a two dimensional parallelized version of the recursive Green s function technique, allowing to treat highly complex structures and geometries. Further development and improvement of the computational algorithm with respect to efficiency, and range of applicability represents a significant part of the project including in particular the extension to three dimensional setups. Extensive applications in two and three dimensions in the above sense are to be performed thereby addressing situations of only a few transversal excitations to full three dimensional quantum transport. The goal is to develop devices that allow for an extensive control of the electronic transport with varying amplitude of the external field.