Magnon-magnon interactions corrected curie temperature in monolayer magnets

Understanding the temperature-dependent properties of intrinsic two-dimensional (2D) magnets is crucial for both fundamental research and technological applications. In this work, we employ nonlinear spin-wave theory, which incorporates magnon-magnon interactions, to evaluate the Curie temperature and spin-wave dispersions of several Cr- and Cu-based 2D magnets. We find that the resulting Curie temperatures are generally lower than those predicted by mean-field and linear-response approaches, yet they more closely match results obtained from accurate quantum Monte Carlo and random phase approximation methods, as well as experimental data. Our approach provides a robust and efficient computational framework for evaluating the corrected Curie temperature of 2D magnets.