Electric field control of anomalous Hall effect in CaIrO3/CaMnO3 heterostructure

We demonstrate an electric field control of an anomalous Hall effect emerging in CaIrO3/CaMnO3 heterostructures. We fabricate both electron-type and hole-type carrier samples by tuning epitaxial strain and, then, control the carrier density in a CaIrO3 layer via electric double layer gating technique. As the Fermi energy of CaIrO3 is tuned close to the Dirac line node, anomalous Hall conductivity is enlarged in both carrier-type samples. This result reveals that the anomalous Hall effect comes from the intrinsic origin, reflecting the Dirac-like dispersion in CaIrO3. We propose that band splitting induced by the interface ferromagnetism yields several band crossing points near the Dirac line node. These points act as a source of the Berry curvature and contribute to the anomalous Hall effect.