Engineering and imaging enhanced spin splittings in solids

自旋电子学是凝聚态物理学中一个重要的新兴领域，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过去二十年来磁存储技术的巨大进步，但事实证明，有源电子设备（如基于自旋的晶体管）更加难以捉摸。一个关键的挑战是创造一个大的自旋分裂的基础电子状态的材料，他们使用的自旋电子设备在室温下工作，具有小的空间尺寸的先决条件。此外，这种自旋分裂必须是电气可控的，以实现器件中的开关。总之，这不仅为快速和节能的电子产品提供了一条道路，而且为实现固态量子器件的电子自旋相干操纵开辟了独特的可能性。我们将进行一系列三个互补的试点研究，旨在确定稳定自旋分裂的新方法，这些自旋分裂比室温大，并且可以使用简单的外部控制进行调节。我们将利用先进的电子能谱来直接观察它们的电子结构，并探索如何调整自旋分裂以最大限度地发挥自旋轨道耦合的作用，从而建立一个微观图像，说明如何在有前途的碳和卤化物基化合物中创建和操纵自旋分裂。我们将寻求解开多重原子轨道，耦合实和动量空间自旋轨道织构，以及拓扑能带结构性质的相互关联的角色。通过这一点，我们不仅将产生新的基本理解，而且还将开发新的组合方法，用于工程自旋分裂的数量级比迄今为止传统半导体系统所实现的要大。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来提高对固体自旋分裂的控制水平，为支持未来的量子技术提供一种材料方法。

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.