Anomalous Hall effect in highly c-plane oriented Mn3Ge/Si(100) thin films grown by pulsed laser deposition

Antiferromagnetic Mn₃Ge with a non-collinear Kagome structures present exciting prospects for exploring Berry curvature driven anomalous Hall effects. Despite substantial progress in bulk systems, the synthesis of crystalline thin films directly on silicon with a hexagonal phase presents a particular challenge unless a buffer layer is employed. In this study, we report the synthesis of single phase c-plane oriented hexagonal Mn₃Ge(0001) films on Si(100) using pulsed laser deposition. Under suitable growth conditions, we obtain layer-by-layer films with atomically flat surfaces and interfaces. High-resolution scanning tunneling microscopy study reveals the detail surface atomic structures, where the surface Mn atoms spontaneously arrange into a Kagome lattice. Tunneling spectroscopy (dI/dV) measurement on the atomically resolved Kagome surface show a minima in local density of states near the Fermi level, likely originated from the Weyl crossings near K points. Despite the nearly vanishing magnetization, magnetotransport measurements in 30 nm Mn₃Ge(0001) films show anomalous Hall resistivity up to 0.41 (μΩ⋅cm) at 2 K. Ourab initiocalculations shed further light on the existence of topological features and the band structures in Mn _{3+x}Ge _{1-x}with increasing Mn concentrationx. The anomalous Hall response at room temperature in crystalline Mn₃Ge films on Si(100) offer promising potential for the development of antiferromagnetic spintronics.