  We report the observation of the antisymmetric magnetoresistance (MR) in
perpendicular magnetized CoTb films with inhomogeneous magnetization
distribution driven by gradient magnetic field. By synchronously charactering
the domain pattern evolution during transport measurements, we demonstrate that
the nonequilibrium currents in the vicinity of tilting domain walls give rise
to such anomalous MR. Moreover, theoretical calculation and analysis reveal
that the geometry factor of the multidomain texture plays a dominant role in
generating the nonequilibrium current. The explicitly established interplay
between the anomalous transport behaviors and the particular domain wall
geometry is essential to deepening understanding of the antisymmetric MR, and
pave a new way for designing novel domain wall electronic devices.
