Two-Channel Anomalous Hall Effect in Epitaxial MnBi2Te4/Mn-Doped Bi2Te3 Heterostructure.

The coexistence of intrinsic magnetism and nontrivial band topology in MnBi2Te4 provides a fertile platform for exploring exotic quantum phenomena. Its tunable spin dynamics under external magnetic fields, combined with the van der Waals (vdW) layered nature, further enables the design of functional heterostructures with controllable magnetic and topological properties. Here, we report an observation of a two-channel anomalous Hall effect (AHE) in an epitaxial MnBi2Te4/Mn-doped Bi2Te3 vdW heterostructure. Notably, the Hall response exhibits unconventional nonsquare Hall hysteresis loops with pronounced hump-dip features, indicative of a two-channel AHE. Through temperature- and angle-dependent Hall measurements, we attribute this two-channel AHE to distinct magnetic critical behaviors of antiferromagnetic MnBi2Te4 and ferromagnetic Mn-doped Bi2Te3 layers and further reveal magnetic phase transitions under rotating magnetic fields. Our results establish a versatile platform for engineering multichannel AHE and provide new opportunities for exploring intertwined magnetic and topological phenomena in tailored vdW heterostructures.