Manipulating Berry curvature of SrRuO3 thin films via epitaxial strain

TL;DR

This paper demonstrates that epitaxial strain can effectively control the magnitude and sign of the anomalous Hall effect in SrRuO3 thin films by tuning Berry curvature, revealing new ways to manipulate quantum material properties.

Contribution

It shows how epitaxial strain alters electronic band structures and Berry curvature, providing a novel method to tune anomalous Hall effects in quantum materials.

Findings

Epitaxial strain changes the sign and magnitude of anomalous Hall resistivity.

Strain induces crystal field splitting and orbital energy reordering.

Rotation of Ru magnetic moments leads to nonmonotonic Hall resistivity behavior.

Abstract

Berry curvature plays a crucial role in exotic electronic states of quantum materials, such as intrinsic anomalous Hall effect. As Berry curvature is highly sensitive to subtle changes of electronic band structures, it can be finely tuned via external stimulus. Here, we demonstrate in SrRuO3 thin films that both the magnitude and sign of anomalous Hall resistivity can be effectively controlled with epitaxial strain. Our first-principles calculations reveal that epitaxial strain induces an additional crystal field splitting and changes the order of Ru d orbital energies, which alters the Berry curvature and leads to the sign and magnitude change of anomalous Hall conductivity. Furthermore, we show that the rotation of Ru magnetic moment in real space of tensile strained sample can result in an exotic nonmonotonic change of anomalous Hall resistivity with the sweeping of magnetic field, resembling the topological Hall effect observed in non-coplanar spin systems. These findings not only deepen our understanding of anomalous Hall effect in SrRuO3 systems, but also provide an effective tuning knob to manipulate Berry curvature and related physical properties in a wide range of quantum materials.