  Writing, erasing and computing are three fundamental operations required by
any working electronic devices. Magnetic skyrmions could be basic bits in
promising in emerging topological spintronic devices. In particular, skyrmions
in chiral magnets have outstanding properties like compact texture, uniform
size and high mobility. However, creating, deleting and driving isolated
skyrmions, as prototypes of aforementioned basic operations, have been grand
challenge in chiral magnets ever since the discovery of skyrmions, and
achieving all these three operations in a single device is highly desirable.
Here, by engineering chiral magnet Co$_8$Zn$_{10}$Mn$_2$ into the customized
micro-devices for in-situ Lorentz transmission electron microscopy
observations, we implement these three operations of skyrmions using nanosecond
current pulses with a low a current density about $10^{10}$ A/m$^2$ at room
temperature. A notched structure can create or delete magnetic skyrmions
depending on the direction and magnitude of current pulses. We further show
that the magnetic skyrmions can be deterministically shifted step-by-step by
current pulses, allowing the establishment of the universal current-velocity
relationship. These experimental results have immediate significance towards
the skyrmion-based memory or logic devices.
