Figure 2: One-dimensional model calculations of domain wall (DW) velocity for wires without pinning.

(a–c) Instantaneous DW velocity v(t) (a), wall magnetization angle (b) and wall tilting angle χ(t) (c) for a fixed current density (J=0.5 × 10⁸ A cm⁻²) flowing through the heavy metal layer. The current pulse length is (t_P) is 100 ns. Definition of the angles and χ(t) are illustrated in the inset of a. Numerical results for the rigid wall, that is, χ(t)=0, with low damping (α=0.01) are shown by the blue dotted line whereas results for the tilted walls (χ(t)≠0) are shown by the black solid (α=0.01) and red dashed (α=0.3) lines. Parameters used: saturation magnetization M_S=1,100 emu cm⁻³, magnetic anisotropy energy K_EFF=3.2 × 10⁶ erg cm⁻³, wall width parameter (exchange constant A=1.5 × 10⁻⁶ erg cm⁻¹), spin Hall angle θ_SH=−0.21, DM exchange constant D=0.24 erg cm⁻², Gilbert α=0.05 and wire width w=5 μm.