Analytical solutions of bubble tracks in periodical propagation structures

摘要

In this paper a general expression is derived that describes tracks of bubbles in current‐access devices, the rotating gradient experiment, etc. A resonance phenomenon resulting from this equation is experimentally verified: The periodical motion of a hard bubble shows a sharp maximum at a certain frequency of operation. This resonance frequency is proportional to the steepness of the magnetic potential well in which the bubble is captured and inversely proportional to the gyrotropic constant of the bubble. Even unichiral bubbles in low damping material may show this phenomenon. From this resonance frequency the gyrotropic constant of the bubble can be accurately determined. The experimental technique of applying a bias field modulation to counter the effects of wall motion coercivity is used. An attempt is made to include this mechanism in the theoretical description.