Thickness‐Tuned Berry Curvature in vdW Epitaxial Cr ₃ Te ₄ Ultrathin Films

Berry curvature in transition metal dichalcogenides (TMDs) critically governs spin‐valley degrees of freedom, nonlinear/quantum electrical transport, and magnetoelectric coupling, underpinning emergent functionalities in valleytronic, magnetoelectric, and optoelectronic devices. Self‐intercalated Cr 1+ δ Te 2 , as a representative magnetic semimetal among TMDs, enables controlled the Berry curvature due to its rigid band shift under external stimuli. In this work, we study the thickness‐tuned Berry curvature, manifested by intrinsic anomalous Hall effect (AHE), in van der Waals (vdW) epitaxial Cr 3 Te 4 ( δ = 0.5) ultrathin films. At low temperatures, the intrinsic AHE of Cr 3 Te 4 ultrathin film has a negative‐polarity below 13 monolayers and positive‐polarity for 22 monolayers. This sign reversal, indicating the Berry curvature modulation, could be attributed to the Fermi level shift caused by Te(CrTe 2 )‐termination at the surface and interface. These findings highlight the crucial role of controlling the electronic structure of vdW materials at atomic scale and pave the way for the design of high‐density, miniaturized topological spintronic devices.