Investigations of magnetic and topological systems using electronic structure and muon-spin spectroscopy

拓扑学是凝聚态物理中的一种组织原理，它使我们能够理解物质的各种状态及其激发。在磁学中，拓扑描述了缺陷，如畴壁、漩涡和天幕，以及各种奇异的基态和带结构。该项目涉及电子结构方法的应用，以了解拓扑系统的潜在电子配置，它们的能级和磁性。这些方法将与使用植入μ子的测量相结合，以灵敏地探测材料的磁性。μ子是亚原子粒子，可以用作微观磁力计，能够测量磁性系统中的有序磁性和动力学。我们计划使用这种方法研究一系列系统，包括低维分子材料，其中通过化学手段可以相互作用以稳定拓扑状态；由磁波动引起的动力学是理解其性质的关键；和磁性weyl半金属，其中带结构的考虑决定了系统的奇异物理特征。我们的方法还将使我们能够评估这些系统中介子停止状态的性质，并评估由零点运动驱动的量子效应，这些效应在这类研究中通常被忽略。

Topology is an organising principle in condensed matterphysics, allowing us to understand a variety of states of matter andtheir excitations. In magnetism, topology describes defects such as domainwalls, vortices and skyrmions and a variety of exotic groundstates and bandstructures.This project involves the application of electronic structuremethods to understand the underlying electronic configuration oftopological systems, their energy levels and magnetism. These methods will becombined with measurements using implanted muons to sensitively probe the magneticproperties of the materials. Muons are subatomic particles which canbe used as microscopic magnetometers, capable of measuring theordered magnetism and dynamics in magnetic systems. We plan to investigate a range of systems using this approach,including low-dimensional molecular materials, where interactions can betuned by chemical means to stabilize topological states;skyrmion-hosting systems where the dynamics caused by magneticfluctuations are key to understanding their properties; and magnetic Weylsemimetals, where bandstructure considerations determine the systems'exotic physical features. Our approach will also allow us to asses thenature of the muon's stopping state in these systems and evaluatequantum effects driven by zero-point motion, that are usually ignoredin these sorts of investigations.