We develop a fully first-principles approach for spin dynamics based on density functional perturbation theory. We demonstrate that the magnon wavefunction can be expressed by a set of electronic wavefunctions obtained from the decomposition of magnon density profile, enabling the direct calculation of magnonic quantities including Berry curvature and Chern number. As a concrete example, we show that monolayer CrI3 can host topological magnons driven by spin-orbit coupling. Our model-free approach paves the way for the comprehensive studies of magnons in real materials.
@article{arxiv.2504.04106,
title = {Fully First-Principles Approach in Studying Topological Magnons},
author = {Xiaoqiang Liu and Ji Feng and Zhenhua Qiao and Qian Niu},
journal= {arXiv preprint arXiv:2504.04106},
year = {2025}
}