Fig. 4: Mechanism of acoustic movement of a magnetic domain wall.

a Time evolution of the energy of the DW normalized by its resting energy. The dotted black curve represents (in this panel and the subsequent panels) the stress of the SAW evaluated at the center of the moving DW. b Time evolution of the width of the DW. c Time evolution of the length of the DW. d The instant velocity of the DW with time. e Position of the DW as a function of time. f The mechanical counterpart of the mechanism described in this article. g Width of the DW as a function of the width of the strip. h Contour plot with the average velocity of the DW as a function of the width of the DW and the wavelength of the SAW. All the simulations were done for an amplitude of the SAW of \(\varepsilon=70\,{{{\rm{ppm}}}}\) propagating from left to right (SAW+). The dotted black straight line in the contour plot has a slope of \(\lambda /4\). The relation between SAW frequency and wavelength is given by the velocity of elastic waves in FeCo, \(v=\lambda {f}=3600\,{{{\rm{m}}}}/{{{\rm{s}}}}\).