Dynamics and Correlations in Frustrated Magnets.

受挫的磁体是相互作用自旋的集体相。它们是相关材料的主要例子，展示了丰富多样的现象，超出了我们对以朗道理论和局部序参数为特征的对称破缺相的规范理解。特别是，量子自旋液体（QSL）的特点是出现了分数化激发和拓扑特性，例如基态简并和拓扑保护边缘激发。qsl对我们对多体相的基本理解很感兴趣，但也有技术应用的潜力。尽管经过几十年的研究，仍然没有明确确定的材料实现QSL。然而，最近几年已经发现了几个有希望的候选系统。此外，在理论方面，已经发明了许多完全可溶的模型系统，可以在严格的水平上理解QSL的性质。本文旨在通过探索范式哈密顿量的动力学特性，弥合理论与实验之间的差距。目标是更好地了解qsl的潜在相关性，并促进它们在实验中的诊断和表征。

Frustrated magnets are collective phases of interacting spins. They are prime examples of Correlated Materials displaying a rich variety of phenomena beyond our canonical understanding of symmetry breaking phases characterised by Landau theory as well as local order parameters. In particular, Quantum Spin Liquids (QSL) are characterised by the emergence of fractionalised excitations and topological properties, e.g. ground state degeneracies and topologically protected edge excitations. QSLs are of interest for our fundamental understanding of many-body phases but have also potential for technological application. Despite decades of research there is still no unambiguously identified materials realisation of a QSL. However, the last few years have seen the discovery of several promising candidate systems. Moreover, on the theoretical side a number of exactly soluble model systems have been invented which allow to understand QSL properties on a rigorous level. This thesis aims at bridging the gap between these recent developments in theory and experiments by exploring the dynamical properties of paradigmatic model Hamiltonians. The goal is to gain a better understanding of the underlying correlations of QSLs and to facilitate their diagnosis and characterisation in experiments.