Electronic, topological, and magneto-optical properties of NiFeMnSn: a first-principles study

We present a detailed first-principles study of the electronic, topological, and magneto-optical properties of the quaternary Heusler compound NiFeMnSn. Using density functional theory (DFT) combined with Berry curvature analysis, we investigate the anomalous transverse transport properties, including the anomalous Hall conductivity (AHC) and anomalous Nernst conductivity (ANC), which attain values of 166.48 S cm^-1 at 0.115 eV and 1.18 A m^-1 K^-1 at -0.25 eV, respectively, within the energy range of -0.3 to +0.3 eV around the Fermi level, highlighting the significant intrinsic contributions arising from Berry curvature effects near the Fermi energy. The topological characteristics are further elucidated through spin-polarized electronic band structure and momentum-resolved Berry curvature mapping, emphasizing the role of spin-orbit coupling (SOC) in generating the anomalous responses. Furthermore, the magneto-optical Kerr effect (MOKE) analysis reveals a maximum Kerr rotation angle of -0.85°, indicating a moderate yet appreciable magneto-optical response. These results identify NiFeMnSn as a promising topological Heusler system exhibiting intertwined electronic, thermal, and magneto-optical phenomena, making it a potential candidate for spintronic and multifunctional device applications.