Single shot detection of the magnetic domain wall motion by using tunnel magnetoresistance effect

Magnetic domain wall (DW) dynamics in submicron ferromagnetic wires has been investigated in real-time regime by using tunneling magneto resistance effect. The DW velocity as a function of magnetic field increases at low field range and takes a local maximum. After stagnation, the velocity starts to increase again. This is a typical signature of the Walker breakdown. Above the Walker field, the real-time traces of individual events show complex behaviors, which suggest the stochastic nature of the DW motion. (C) 2008 The Japan Society of Applied Physics.