| Abstract: | Quantum many-body systems can exhibit behavior far richer than that of their individual constituents, giving rise to new collective phenomena and emergent quasiparticles. Frustrated quantum magnets provide a striking setting for such emergence, where competing interactions can suppress conventional magnetic order and stabilize quantum-disordered states known as spin liquids. In this talk, I will discuss several paradigmatic models of low-dimensional quantum magnets, and how a magnetic field can be used to probe their emergent physics. I will show how the field can reveal effective interactions between fractionalized excitations through their dynamics in one-dimensional spin chains, and argue that it can provide a route to identifying and characterizing the quantum-disordered state in a two-dimensional triangular-lattice antiferromagnet. |