  We theoretically analyzed a magnetic wall confined in a nano-contact spin
valve paying special attention to the penetration of the magnetic wall into
thin ferromagnetic electrodes. We showed that, compared with the Bloch wall,
the penetration of the Neel wall is suppressed by increases of the
demagnetization energy. We found the optimal conditions of the radius and
height of the nano-contact to maximize the power of the current-induced
oscillation of the magnetic wall. We also found that the thermal stability of
the Bloch wall increases when the nano-contact's radius increases or height
decreases.
