Engineering and imaging enhanced spin splittings in solids

凝聚态物理学中一个重要的新兴领域是自旋电子学，它是利用电子自旋的电子学的一种变体。虽然这一概念支撑了磁存储技术在过去二十年中的巨大进步，但有源电子器件（如自旋晶体管）已被证明更加难以捉摸。一个关键的挑战是创建一个大的自旋分裂的材料的底层电子状态，一个先决条件，它们用于自旋电子器件在室温下工作，并具有小的空间尺寸。此外，这种自旋分裂必须是电可控的，以实现器件中的切换。总之，这不仅有望实现快速和节能的电子产品，而且将为实现固态量子器件的电子自旋相干操纵开辟独特的可能性。我们将进行一系列的三个互补的试点研究，旨在确定新的方法来稳定自旋分裂是大的相比，室温和可调使用简单的外部控制。我们将建立一个如何在有前途的硫属元素和卤化物基化合物中产生和操纵自旋分裂的微观图像，使用先进的电子光谱法直接可视化它们的电子结构，并探索如何调整以最大限度地发挥自旋轨道耦合的作用。我们将试图解开多个原子轨道，耦合真实的和动量空间自旋轨道纹理，和拓扑能带结构属性的相互关联的作用。通过这一点，我们不仅将产生新的基本理解，而且还开发了新的组合方法，用于工程自旋分裂的数量级大于迄今为止在传统的基于磁阻的系统中实现的数量级。该项目得到了来自英国和日本的合作伙伴的支持，在材料合成和理论建模方面带来了互补的专业知识和能力。它将利用英国独特的实验室基础设施以及关键的国家设施，推动对固体自旋分裂的控制达到新的水平，为未来的量子技术提供材料方法。

An important emerging field in condensed-matter physics is spintronics, a variant of electronics exploiting the electron's spin. While this concept underpins the dramatic improvements in magnetic storage technology seen over the last two decades, active electronic devices such as spin-based transistors have proved much more elusive. A key challenge is to create a large spin splitting of the underlying electronic states of materials, a pre-requisite to their use for spintronic devices operating at room temperature and having small spatial dimensions. Moreover, this spin splitting must be electrically controllable to achieve switching in a device. Together, this would not only promise a route to fast and energy-efficient electronics, but would open unique possibilities for achieving coherent manipulation of electron spins for solid-state quantum devices. We will undertake a series of three complementary pilot studies aimed at identifying new approaches to stabilise spin splittings that are large compared to room temperature and that are tuneable using simple external control. We will build up a microscopic picture of how spin splitting can be created and manipulated in promising chalcogen and halide-based compounds, using advanced electron spectroscopy to directly visualise their electronic structure and probe how it can be tuned to maximise the effects of spin-orbit coupling. We will seek to disentangle the interconnected roles of multiple atomic orbitals, coupled real and momentum-space spin-orbital textures, and topological band structure properties. Through this, we will not only generate new fundamental understanding, but also develop novel combined methodologies for engineering spin splittings orders of magnitude larger than have been achieved in conventional semiconductor-based systems to date. The project is supported by partners from the UK and Japan, brining complementary expertise and capability in materials synthesis and theoretical modeling. It will utilise unique laboratory infrastructure in the UK as well as key national facilities to advance new levels of control over spin splitting in solids, providing a materials approach to underpin future quantum technologies.