Influence of the carrier signal phase on the formation of "Dark" spin wave envelope solitons in magnetic films

A process of formation of "dark" spin wave envelope solitons in magnetic films is considered. It is shown that a 180/spl deg/ phase shift in the carrier frequency of an input rectangular negative radio-pulse is necessary to create a single "dark" envelope soliton. The input signal with no phase shift can create only a pair (or several pairs) of "dark" envelope solitons. A new interpretation of a recent experimental observation of "dark" spin wave envelope soliton formation in yttrium-iron garnet (YIG) films is given.