A conductor crossing problem in magnetic bubble memories

Bubble propagation across a conductor depends, among other considerations, on the magnetostatic energy of the bubble‐Permalloy interaction and strain due to patterned metallization layers. Previously neglected, another consideration—bias field distortion in the neighborhood of the crossing—is discussed here. Poles induced by the bias field on a Permalloy element shaped to conform to a conductor produce field components parallel and transverse to the nominal bias. In traversing an isolated crossing at right angles to the conductor length and at a fixed altitude within the magnetic garnet, one calculates for the distortion bias maxima near the conductor edges and a minimum at the center. To obtain a tractable solution for the bias field as a function of coordinates a two‐dimensional model was chosen for the conductor crossing: an infinite half space of infinitely permeable Permalloy with a circular depression. At points infinitely removed from the depression which houses the conductor the complex field H=Hx...