  Due to their non-trivial topology, skyrmions describe deflected trajectories,
which hinders their straight propagation in nanotracks and can lead to their
annihilation at the track edges. This deflection is caused by a gyrotropic
force proportional to the topological charge and the angular momentum density
of the host film. In this article we present clear evidence of the reversal of
the topological deflection angle of skyrmions with the sign of angular momentum
density. We measured the skyrmion trajectories across the angular momentum
compensation temperature (TAC) in GdCo thin films, a rare earth/transition
metal ferrimagnetic alloy. The sample composition was used to engineer the
skyrmion stability below and above the TAC. A refined comparison of their
dynamical properties evidenced a reversal of the skyrmions deflection angle
with the total angular momentum density. This reversal is a clear demonstration
of the possibility of tuning the skyrmion deflection angle in ferrimagnetic
materials and paves the way for deflection-free skyrmion devices.
