  Magnetic skyrmions are topologically-protected spin textures existing in
helimagentic materials, which can be utilized as information carriers for
non-volatile memories and logic circuits in spintronics. Searching simple and
controllable way to create isolated magnetic skyrmions is desirable for further
technology developments and industrial designs. Based on micromagnetic
simulations, we show that the temporal dissipative structure can be developed
in the T-shaped helimagnetic nanojunction when it is driven to the
far-from-equilibrium regime by a constant spin-polarized current. Then the
magnetic skyrmions can be continuously nucleated during the periodic
magnetization dynamics of the nanojunction. We have systematically investigated
the effects of current density, Dzyaloshinskii-Moriya interaction, external
magnetic field, and thermal fluctuation on the nucleation dynamics of the
magnetic skyrmions. Our results here suggest a novel and promising mechanism to
continuously create magnetic skyrmions for the development of skyrmion-based
spintronics devices.
