Domain wall deceleration in a garnet film by femtosecond laser pulses

Using the least squares method, approximating functions for the experimental dependence of the total velocity of the antiferromagnetic vortices on the domain wall velocity were selected. Using the obtained functions and the relation between the vortex velocities and the domain wall velocity, the dependences of the vortex velocity along the domain wall u on the domain wall velocity v were calculated. It was found that if the velocity of the domain wall is less than a certain critical value, the dependence u(v) is not determined. This confirms the earlier conclusion about the impossibility of the antiferromagnetic vortices existence inside the domain wall if it moves at a speed less than the sound velocity.