Magnetic domain wall waves, parametrically excited in a stripe domain lattice in a garnet film

Waves of magnetic domain wall motion in an array of straight, aligned stripe domains have been detected by observations of optical diffraction from the array. When the array is excited by a spatially uniform rf drive field of amplitude greater than 0.25 Oe peak, at a frequency near the resonant frequency of the uniform ’’breathing’’ mode of the array, dynamic spots appear in the diffraction pattern. The dynamic spot positions correspond to wave vectors oblique to the stripes, while the rf intensity variation suggests that the waves are parametrically excited at one-half the frequency of the spatially uniform mode.