Dimensional crossover characterized by distribution of magnetic domain wall creep velocity.

We studied the magnetic domain wall (DW) creep motion in two driving forces: external magnetic field and spin Hall torque (SHT). The dimensional crossover from two to one dimension is identified by looking at the distribution width of the DW velocity depending on the wire width. The distribution widths are found to be similar regardless of the driving forces in narrow wires, whereas they show nonnegligible differences depending on the driving force in wide wires. Therefore, the dimensional crossover implies that the effective magnetic field induced by the SHT becomes equivalent to the external magnetic field only when the wire is considered as one-dimensional. [ABSTRACT FROM AUTHOR]