  We theoretically study the current-perpendicular-to-plane magnetoresistance
of a domain wall confined in a current-confined-path (CCP) structure made of a
nano-oxide-layer (NOL). In order to calculate the MR ratio of the system, the
continuity equations for charge and spin currents are numerically solved with
the three-dimensional CCP geometry by use of finite element method. It is
confirmed that the MR ratio is enhanced by the CCP structure, which is
consistent with the experimental results.
