A simple method for computing wall twist in high-Q bubble materials

First-order perturbation of the one-dimensional structure for the wall surrounding a bubble domain, lead to a set of linear differential equations, which should determine the wall twist for any magnetic material with a large quality factor Q provided the wall is stationary. A first-order solution of these equations is given in terms of two linear integrals whose numerical evaluation is much simpler than the evaluation of wall structure by minimizing numerically the wall energy, as has been done so far. Examples are given for the wall twist thus computed for several film thicknesses, which should give an idea of what the twist is when Q is large enough. For medium Q, however, the accuracy of the method turns out to be inadequate.