Dynamics of thermal effects in the spin-wave theory of quantum antiferromagnets

We derive a master equation that allows us to study non-equilibrium dynamics of a quantum antiferromagnet. By resorting to spin-wave theory, we obtain a closed analytic form for the magnon decay rates. These turn out to be closely related to form factors, which are experimentally accessible by means of neutron and Raman scattering. Furthermore, we compute the time evolution of the staggered magnetization showing that, for moderate temperatures, the magnetic order is not spoiled even if the coupling is fully isotropic.

► We derive a master equation that allows us to study non-equilibrium dynamics due to the thermal phonons in the lattice. ► We give a closed analytic form for the magnon decay rates and show these ones turn out to be closely related to form factors. ► We compute the non-equilibrium time evolution of the staggered magnetization and correlation functions.