  The motion of magnetic domain walls in ultrathin magnetic heterostructures
driven by current via the spin Hall torque is described. We show results from
perpendicularly magnetized CoFeB|MgO heterostructures with various heavy metal
underlayers. The domain wall moves along or against the current flow depending
on the underlayer material. The direction to which the domain wall moves is
associated with the chirality of the domain wall spiral formed in these
heterostructures. The one-dimensional model is used to describe the
experimental results and extract parameters such as the Dzyaloshinskii-Moriya
exchange constant which is responsible for the formation of the domain wall
spiral. Fascinating effects arising from the control of interfaces in magnetic
heterostructures are described.
