Shining Light On Quantum Magnetism
Abstract: The manner in which localized spins interact in magnetic insulators is a strongly correlated many-body problem. To date, very few exactly solvable models of such spin
interactions exist and those that do are often highly idealized. Therefore, intense experimental effort is devoted to characterizing the ground states of such "quantum
magnets." In this talk, I will demonstrate that low energy optical experiments are exceptionally well suited for characterizing such magnetic ground states by providing a detailed look at their excitation spectrum. I will specifically focus on a FeSc2S4, a unique system in which both orbital and spin degrees of freedom conspire to form an entangled "spin-orbital liquid" ground state with long range entanglement on the edge of quantum criticality.