Exceptional dynamics of interacting spin liquids

Quantum spin liquids are emergent gauge theories with associated fractionalized excitations and emergent gauge fields. A prominent open question is how a spin liquid is sharply characterized in experiments, with traditional approaches focusing on mean-field theory.

Here, we show that the dynamics of interacting spin liquids can display non-hermitian phenomenology which is completely absent in the non-interacting version. We demonstrate this in two prominent cases through the effects of phonons and disorder on a Kitaev spin liquid. We show the occurrence of exceptional points and rings which are reflected in spectroscopic observables such as the dynamic structure factor measured in neutron scattering. The results point to a rich phenomenology of dynamics in spin liquids if interactions are taken into account and necessity for such studies to make connections with experiments.