Calculation method of GMR head response for double layered perpendicular medium

摘要

A new field calculation method was developed for the reading process that involves a doubleJayered medium with a soft underlayer. The image fields due to both the underlayer and the ABS have to be taken into consideration. It was found that the field can be expressed in an equation similar to that describing multiple reflection of light in an optical multilayer, except that the scalar terms in the optical system have to be replaced with tensor terms with Fourier components as bases. This field, in turn, may be used as an input to a micromagnetic simulation model for GMR head to give the reproduced signal.