Anomalous Hall effect from inter-superlattice scattering in a noncollinear antiferromagnet

Superlattice formation dictates the physical properties of many materials, including the nature of the ground state in magnetic materials. Chemical composition is commonly considered to be the primary determinant of superlattice identity, especially in intercalation compounds. In this talk, I will show results demonstrating that, contrary to this conventional wisdom, kinetic control of superlattice growth can lead to the coexistence of disparate domains within a compositionally “perfect” single crystal. We report a new bulk noncollinear antiferromagnetic ground state in an intercalated transition metal dichalcogenide in which scattering between bulk and minority superlattice domains engenders complex magnetotransport below the Néel temperature, including an anomalous Hall effect. We characterize the magnetic phases in different domains, image their nanoscale morphology, and propose a mechanism for nucleation and growth. These results provide a blueprint for the deliberate engineering of macroscopic transport responses via microscopic patterning of magnetic exchange interactions in superlattice domains.