Computational quantum transport in mesoscopic electronic waveguides

我们将研究具有高数值复杂性的介观系统中的量子输运，这将导致输运性质的高度可变性。具体地说，我们研究了外加磁场对复杂电子波导传输的影响。后者是由具有可调谐光谱的不同量子点的有限阵列形成的。点的几何形状、引线的位置，特别是均匀或非均匀磁场的施加，影响电子动力学，并因此影响导波的传输特性。改变和优化阵列的几何结构、有限温度引起的热展宽、对电流的非相干贡献以及自旋相关的输运是需要研究的相关方面。计算格式基于递归格林S函数技术的二维并行化版本，允许处理高度复杂的结构和几何。计算算法在效率和适用范围方面的进一步发展和改进是该项目的一个重要部分，特别包括将其扩展到三维设置。在上述意义上，将在二维和三维中进行广泛的应用，从而解决仅对全三维量子传输的几个横向激发的情况。我们的目标是开发一种设备，允许广泛地控制外部磁场的不同幅度的电子传输。

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.