  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.
