Shifting of domains in thin magnetic film strips excited by position- and time-dependent easy-axis fields

Assuming that domain walls are straight and infinitely thin, it is possible to derive a system of equations of motion for any number of domain walls in thin film strips with in-plane magnetization. Considering the influence of the demagnetizing fields, the "pulsed motion\´ of domains in a field with constant field gradient is analysed analytically and numerically by these equations that hold true for any position- and time-dependent fields. The theoretically expected dependence of the domain velocity on pulse frequency and amplitude is discussed. If there are several domains, one must take into consideration additional interactions between each other. Those interactions appear in form of an effective internal field difference ΔHwin case of two neighboring domains. The criteria for moving as under during the pulsation are discussed. In comparison with a single domain neighbouring domains change the Hw-dependence on domain width. Smaller remanent domain width and a reduced collapse field for domains result from this.