Magnetic skyrmions are topologically non-trivial spin textures of potential
interest for future information storage applications, and for such purposes,
the control and understanding of single skyrmion creation is required. A scheme
is analyzed to create single N\'{e}el-type and Bloch-type skyrmions in
helimagnetic thin films utilizing the dynamical excitations induced by the
Oersted field and the spin transfer torque given by a vertically injected
spin-polarized current. A topological charge analysis using a lattice version
of the topological charge provides insight into the locally triggered
transition from a trivial to a non-trivial topological spin texture of the
N\'{e}el or Bloch type skyrmion. The topological protection of the magnetic
skyrmion is determined by the symmetric Heisenberg exchange energy. The
critical switching current density is $\sim10^{7}\thinspace\textrm{A/cm}^{2}$,
which decreases with the easy-plane type uniaxial anisotropy and thermal
fluctuations. In-plane spin polarization of the injected current performs
better than out-of-plane polarization, and it provides ultrafast switching
times (within 100 ps) and reliable switching outcomes.
