Bubble domain field access device modeling part I: The magnetization problem

A continuum magnetostatic energy model for describing field access bubble domain devices is introduced and a prescription for solving the modeling problem is given. Minimization of the magnetostatic energy yields an integral equation defining the magnetization in the permalloy and the solution of this magnetization problem is described in detail. Application of the formalism to the calculation of demagnetizing fields for uniformly magnetized patterns is discussed as are the solutions of the magnetization problem for simple geometries. Techniques for improving the speed and convergence of the calculations are suggested based upon the proposed interpolation scheme and are compared to other computational methods such as Fourier series expansion. In a second paper (Part II) the solution of the magnetization problem is used to calculate the drive fields acting on the bubble as well as to calculate the magnetoresistance of a chevron stretcher detector under various in-plane drive field conditions.