2025/09/08 by Anita Halder, Declan Nell, Halder, Anita +7
Materials Science · Physics and Astronomy · #2D Materials and Applications #FOS: Physical sciences #Heusler alloys: electronic and magnetic properties #Materials Science (cond-mat.mtrl-sci) #Quantum and electron transport phenomena
paper · pdf · doi:10.48550/arxiv.2509.06823
openalex publication_date 2025/09/08 · openalex created_date 2025/10/11 · openalex updated_date 2026/07/28
We present a systematic first-principles investigation of linear-response spin-dependent quantum transport in the van der Waals ferromagnets Fe3GeTe2, Fe4GeTe2, Fe5GeTe2, and Fe3GaTe2. Using density functional theory combined with the non-equilibrium Green's function formalism, we compute their Fermi surfaces, transmission coefficients, and orbital-projected density of states. All compounds exhibit nearly half-metallic conductance along the out-of-plane direction. This is characterized by a finite transmission coefficient for one spin channel and a gap in the other, resulting in spin polarization values exceeding 90% in the bulk. Notably, Fe3GaTe2 displays the ideal half-metallic behavior, with the Fermi energy located deep in the spin-down transmission gap. We further show that this high spin polarization is preserved in bilayer magnetic tunnel junctions, which exhibit a large tunnel magnetoresistance of the order of several hundred percent. This findings underscore the promise of these materials, and in particular of Fe3GaTe2, for spintronics applications.