Magnon decays in dipolar Rydberg quantum simiulators

Spin-waves or magnons are the elementary quanta of excitation on top of ordered magnetic phases, such as ferromagnets and antiferromagnets. Although generally stable in short-range interacting systems, a magnon can spontaneously decay into two in presence of a magnetic field. Motivated by the recent experimental realization of magnetism in long-range interacting Rydberg arrays, we will consider the problem of stability of magnons in presence of an external field. We will discuss symmetry and kinematic constraints on such decays, and the essential differences between short-range and long-range interacting models. If time permits, we will comment on the physical consequences of magnon decay as they pertain to correlation functions and spin transport.