  Magnetic materials hosting topological spin textures like magnetic skyrmion
exhibit nontrivial Hall effect, namely, topological Hall effect (THE). In this
study, we demonstrate the emergence of THE in thin films of half-metallic
perovskite manganites. To stabilize magnetic skyrmions, we control the
perpendicular magnetic anisotropy by imposing a compressive epitaxial strain as
well as by introducing a small Ru doping. When the perpendicular magnetic
anisotropy is tuned so that it is balanced with the magnetic dipolar
interaction, the film exhibits a sizable THE in a magnetization reversal
process. Real-space observations indicate the formation of skyrmions and some
of them have high topological charge number. The present result opens up the
possibility for novel functionalities that emerge under keen competition
between the skyrmion phase and other rich phases of perovskite manganites with
various orders in spin, charge, and orbital degrees of freedom.
