Coherent spin transport in semiconductors

在之前的资助期内，我们已经证明了非故意掺杂的氧化锌外延层中施主电子的自旋退相时间可以超过30 ns。在下一个资助期，我们建议探索是否可以通过光学手段来操纵来自不同施主原子的邻近施主自旋之间的磁交换相互作用。此外，我们还建议将我们以前的电自旋注入氧化锌的实验扩展到时间域，使用电泵浦/光学探测方案来揭示注入电子自旋的相位信息。在第二个焦点中，我们建议将我们的自旋注入和输运研究扩展到硅基纳米结构。我们将使用非局域自旋阀几何方法，使用铁磁电极和Al_2O_3作为注入势垒，在硅中进行自旋注入和探测。对于时间分辨的全电学研究，我们将开发一种新的电泵探测实验，该实验将用于相干自旋电流的相敏检测。

Within the previous funding period, we have shown that spin dephasing times of donor electrons in unintentionally doped ZnO epilayers can exceed 30 ns. For the next funding period, we propose to explore whether the magnetic exchange interaction between neighbouring donor spins from different donor atoms can be manipulated by optical means. Furthermore, we propose to extend our previous experiments on electrical spin injection into ZnO towards the time-domain using an electrical pump/- optical probe scheme to unveil phase information of the injected electron spins. In a second focus, we propose to extend our spin injection and transport studies to Si-based nanostructures. We will use a non-local spin valve geomatry for spin injection and detection in Si using ferromagnetic electrodes and Al2O3 as injection barrier. For time-resolved all-electrical studies, we will exploit a novel electrical pump probe experiment, which shall be used for phase sensitive detection of coherent spin currents.