Linear and nonlinear spin dynamics in multi-domain magnetoelastic antiferromagnets

Antiferromagnets (AFs) have recently surged as a prominent material platform for next-generation spintronic devices. Here we focus on the dynamics of the domain walls in AFs in the presence of magnetoelasticity. Based on a macroscopic phenomenological model, we demonstrate that magnetoelasticity defines both the equilibrium magnetic structure and dynamical magnetic properties of easy-plane AFs in linear and nonlinear regimes. We employ our model to treat non-homogeneous magnetic textures, namely an AF in a multi-domain state. Calculations of the eigen-modes of collective spin excitations and of the domain walls themselves are reported, even considering different kinds of domains. We also compare the output of our model with experimental results, substantiating the empirical observation, and showing that domain walls majorly affect the optically driven ultrafast nonlinear spin dynamics. Our model and its potential developments can become a general platform to handle a wide set of key concepts and physical regimes pivotal for further bolstering the research area of spintronics. (paper)