Revealing Fermi surface topologies through synchrotron Compton scattering and ab initio calculations

通过同步加速器康普顿散射和从头计算揭示费米表面拓扑

• 批准号: 2267206
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2267206
• 关键词: Revealing; Fermi; surface; topologies; through

The Fermi surface is one of the most important concepts in the physics of metals [1]. Its shape is important for understanding the properties and behaviours of a metal (e.g. magnetic order, superconductivity, charge- and spin-density waves), and measuring it is a challenging but important task. Compton scattering, in which a photon is inelastically scattered by an electron in the material being studied, can uniquely provide access to the ground-state electronic wavefunction, and also the Fermi surface. Fermi surface measurements by Compton scattering are not limited by short electron mean free paths or by low temperatures. The experiments can be performed with, or without an applied magnetic field, and - most importantly - it probes the bulk, rather than the surface [2]. For example, our recent work on PdCrO2 was able to elucidate the role of the Fermi surface in mediating the frustrated magnetic interactions between local Cr magnetic moments [3]. The group is currently working on a diverse range of materials, including topological superconductors, high-entropy alloys, half-metallic ferromagnets, (topological) Kondo insulators and correlated oxides. The student will have the opportunity of operating in an environment where experimental work is supported and inspired by electronic structure theory developed and executed within the group. The student would be expected to take an active role in these theoretical endeavours, which most recently have focused on being able to treat more strongly correlated electronic materials through techniques such as DMFT and GW. The project would suit someone who has a strong interest in computational theoretical condensed matter physics but would like to maintain a very close connection to experiment. As part of this project, you might also be involved with experiments at national and international facilities (such as SPring-8 in Japan).

费米面是金属物理学中最重要的概念之一[1]。它的形状对于理解金属的性质和行为（例如磁序、超导性、电荷和自旋密度波）非常重要，测量它是一项具有挑战性但重要的任务。康普顿散射（其中光子被所研究材料中的电子非弹性散射）可以独特地提供基态电子波函数以及费米表面。通过康普顿散射进行的费米表面测量不受短电子平均自由程或低温的限制。这些实验可以在施加或不施加磁场的情况下进行，而且最重要的是，它探测的是整体，而不是表面 [2]。例如，我们最近对 PdCrO2 的研究能够阐明费米表面在调节局部 Cr 磁矩之间受阻磁相互作用中的作用 [3]。该小组目前正在研究各种材料，包括拓扑超导体、高熵合金、半金属铁磁体、（拓扑）近藤绝缘体和相关氧化物。学生将有机会在实验工作受到小组内开发和执行的电子结构理论支持和启发的环境中进行操作。学生将被期望在这些理论工作中发挥积极作用，这些理论工作最近的重点是能够通过 DMFT 和 GW 等技术处理更强相关的电子材料。该项目适合对计算理论凝聚态物理有浓厚兴趣但希望与实验保持非常密切联系的人。作为该项目的一部分，您还可能参与国家和国际设施（例如日本的 SPring-8）的实验。