Electric field control of anomalous Hall effect in CaIrO$_3$/CaMnO$_3$ heterostructure

TL;DR

This study demonstrates electric field control of the anomalous Hall effect in CaIrO₃/CaMnO₃ heterostructures, revealing an intrinsic origin linked to Dirac-like dispersion and interface ferromagnetism.

Contribution

It introduces a method to tune the anomalous Hall effect via electric double layer gating in heterostructures with Dirac-like dispersion.

Findings

Anomalous Hall conductivity is enhanced near the Dirac line node.

Electric double layer gating effectively tunes carrier density.

Interface ferromagnetism induces band splitting affecting Berry curvature.

Abstract

We demonstrate an electric field control of anomalous Hall effect emerging in CaIrO$_3$/CaMnO$_3$ heterostructures. We fabricate both electron-type and hole-type carrier samples by tuning epitaxial strain and then control the carrier density in CaIrO$_3$ layer via electric double layer gating technique. As the Fermi energy of CaIrO$_3$ 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 CaIrO$_3$. We propose that band splitting induced by the interface ferromagnetism yields several band crossing points near the Dirac line node. These points play as a source of the Berry curvature and contribute to the anomalous Hall effect.