Anomalous Nernst effect characterizing high-Chern number in Bi/FeBi₂Te₄ heterostructure

Abstract Quantum anomalous Hall effect (QAHE) characterized by the presence of multiple non-dissipertive edge conduction channels has garnered substantial research interest owing to its applications in energy-conserving electronic devices. However, the observation is constrained by extremely low temperatures, which pose challenges for practical implementation. In the context, we delineate the interrelationship between the anomalous Nernst effect and the quantum anomalous Hall effect through Berry curvature in the Bi/FeBi 2 Te 4 heterostructure. Initially, under the application of strain engineering, we achieve precise regulation of the high-Chern number within the Bi/FeBi 2 Te 4 heterostructure. We observe that the Berry curvature of systems with different Chern numbers varies significantly. Consequently, in diverse systems, anomalous Nernst conductance (ANC) induced by Berry curvature also has obvious differences. Next, through first-principles calculation, we use ANC to characterize distinct quantum anomalous Hall insulators. Notably, at elevated temperature, we identify several ANC energy intervals with characterization properties near the Fermi level. Our results proffer a feasible approach for delineating the QAHE through detectable thermoelectric signals.