Unusual Behavior of Domain Wall under an External Magnetic Field
We show that the unusual dependence on the magnetic field is observed in the process of pinning and depinning of a domain wall. We found that the transmission probability of a domain wall through the magnetic nanowire displays a significant drop after exceeding the threshold driving field value. This peculiar behavior contradicting the naive picture that a domain wall should be more mobile in the higher magnetic field is discussed based on the results of the micromagnetics simulation taking into account the edge roughness and the thermal activation. It is found that the switching of the core magnetization in a vortex domain wall due to the Walker breakdown enhances the pinning probability of the moving wall, suggesting that the dynamical pinning of the domain wall plays an important role in the operation of domain-wall-based spintronics devices.
Figures: Upper image: Magnetic configuration of domain wall in a NiFe wire with 190 nm of wire width simulated by micromagnetics. Lower panel: Transmission probabilities as a function of a driving field for the wires with different widths.
“Dynamical Pinning of a Domain Wall in a Magnetic Nanowire Induced by Walker Breakdown”
by H. Tanigawa, T. Koyama, M. Bartkowiak, S. Kasai, K. Kobayashi, Y. Nakatani, and T. Ono
Phys. Rev. Lett., 101, 207203 (2008).