Imaging the effect of nanoscale static and dynamic disorder on topological spin currents

自从量子霍尔效应的发现，以及随后与拓扑学的联系，以及2016年诺贝尔奖的颁发，拓扑材料一直是物理学中一个奇特而有趣的部分。它们在电子和信息技术方面的潜在应用，再加上对更基础物理的洞察，使它们成为一种有希望继续研究的材料。然而，尽管在这一领域取得了巨大的进步，但我们对材料的了解仅限于单晶，很少关注缺陷或晶界的作用。器件的应用可能需要薄膜技术，缺陷和增益边界的作用将变得至关重要。在这个项目中，我们将研究和理解纳米尺度的静态无序和动态无序对拓扑自旋流的影响。我们将使用一种新的实验方法，泵浦-探测显微镜，使我们能够达到10fS的分辨率，并在空间上解决无序和纳米尺度异质性的影响。这将与第一原理理论建模相结合，以建立对这类材料如何表现出远离完美单晶限制的新理解，这是目前的技术状态。阐明可能出现的新现象，并回答与设备相关的问题。

Since the discovery of the quantum Hall effect, the subsequent links to topology, and the granting of the 2016 Nobel prize, topological materials have been an exotic and intriguing part of physics. Their potential application to electronics, and information technology coupled with the insights to more fundamental physics makes them a promising material to continue to investigate. However, despite tremendous advances in the area, our understanding of the materials is limited to single crystals with little attention paid to the role of defects or grain boundaries. Device application may require thin films technologies and the role of defects and gain boundaries will become critical. In this project, we will study and understand the effect of nanoscale static and dynamic disorder on topological spin currents. We will use a novel experimental methodology, pump-probe microscopy, allowing us to reach resolution down to 10fs and spatially resolve the effects of disorder and nanoscale heterogeneity. This will be combined with first principals theoretical modelling, to build up a new understanding of how this class of materials behaves away from the perfect single crystal limit which is the current state of the art. Shedding light on possible new phenomena and answer pressing, device relevant questions.