  We examine driven skyrmion dynamics in systems with inhomogeneous pinning
where a strip of strong pinning coexists with a region containing no pinning.
For driving parallel to the strip, we find that the initial skyrmion motion is
confined to the unpinned region and the skyrmion Hall angle is zero. At larger
drives, a transition occurs to a phase in which motion also appears within the
pinned region, creating a shear band in the skyrmion velocity, while the
skyrmion Hall angle is still zero. As the drive increases further, the flow
becomes disordered and the skyrmion Hall angle increases with drive until
saturating at the highest drives when the system transitions into a moving
crystal phase. The different dynamic phases are associated with velocity and
density gradients across the pinning boundaries. We map out the dynamic phases
as a function of pinning strength, skyrmion density, and Magnus force strength,
and correlate the phase boundaries with features in the velocity-force curves
and changes in the local and global ordering of the skyrmion structure. For
large Magnus forces, the shear banding instability is replaced by large scale
intermittent flow in the pinned region accompanied by simultaneous motion
perpendicular to the direction of the drive, which appears as oscillations in
the transport curves. We also examine the case of a drive applied perpendicular
to the strip, where we find a jamming effect in which the skyrmion flow is
blocked by skyrmion-skyrmion interactions until the drive is large enough to
induce plastic flow.
