Density functional theory calculations are carried out to study the electronic and topological properties of MPX3 (M = Mn, Fe, Co, Ni, and X = S, Se) monolayers in the ferromagnetic (FM) metastable magnetic state. We find that FM MnPSe3 monolayers host topological semimetal signatures that are gapped out when spin-orbit coupling (SOC) is included. These findings are supported by explicit calculations of the Berry curvature and the Chern number. The choice of the Hubbard-U parameter to describe the d-electrons is thoroughly discussed, as well as the influence of using a hybrid-functional approach. The presence of band inversions and the associated topological features are found to be formalism-dependent. Nevertheless, routes to achieve the topological phase via the application of external biaxial strain are demonstrated. Within the hybrid-functional picture, topological band structures are recovered under a pressure of 15% (17 GPa). The present work provides a potential avenue for uncovering new topological phases in metastable ferromagnetic phases.
@article{arxiv.2212.02431,
title = {Prediction of topological phases in metastable ferromagnetic MPX$_3$ monolayers},
author = {Natalya Sheremetyeva and Ilyoun Na and Anay Saraf and Sinéad M. Griffin and Geoffroy Hautier},
journal= {arXiv preprint arXiv:2212.02431},
year = {2023}
}