Formation of normal and hard bubbles by cutting strip domains

This paper describes a new method in which normal bubbles and hard bubbles having arbitrary values of collapse field within a range allowable for a given sample can be produced merely by cutting straight strip domains with single-pulse currents applied to a pair of parallel strip conductors. When cuts are made along the inner edges of the conductor strips, normal bubbles result, while hard bubbles result when cuts are made along the outer edges. The collapse field of hard bubbles thus produced depends upon the orientation of the original straight strip domains with respect to the conductors. Moreover, the "sense" of hard bubbles is uniquely determined by whether the straight strip domains are tilted to the right or left of the perpendicular to the conductors before pulsing. An attempt is made to interpret the experimental results in terms of a mechanism in which a pulse field "overdrives" a domain wall to produce Bloch lines.