Abstract

Field theoretic descriptions are a powerful tool to capture the emergent, collective behaviour of strongly correlated many body systems on large scales. Gauge field theories in particular are of special interest in modern physics, due to their connection to topological behaviour and fractionalisation. Through this modelling, the original dense system of strongly interacting degrees of freedom can be interpreted as an emergent vacuum with quasiparticle excitations whose properties are closely related to the nature of the emergent gauge fields. This change in perspective affords us an unprecedented insight into the properties of these systems and in predicting new behaviour. We will review some of these concepts in a model and material that has become a paradigmatic case in point: spin ice. We shall further discuss how microscopic details can lead to surprisingly important effects in the cooperative dynamics of these systems, which becomes underpinned by near-fractal structures.