  Symmetry breaking together with strong spin-orbit interaction give rise to
many exciting phenomena within condensed matter physics. A recent example is
the existence of chiral spin textures, which are observed in magnetic systems
lacking inversion symmetry. These chiral spin textures, including domain walls
and magnetic skyrmions, are both fundamentally interesting and technologically
promising. For example, they can be driven very efficiently by electrical
currents, and exhibit many new physical properties determined by their
real-space topological characteristics. Depending on the details of the
competing interactions, these spin textures exist in different parameter
spaces. However, the governing mechanism underlying their physical behaviors
remain essentially the same. In this review article, the fundamental
topological physics underlying these chiral spin textures, the key factors for
materials optimization, and current developments and future challenges will be
discussed. In the end, a few promising directions that will advance the
development of skyrmion based spintronics will be highlighted.
