Media-to-sensor demagnetization matrix and its applications in micromagnetic simulation of readback process

The media-to-sensor demagnetization matrix is derived for the calculation of the media magnetic field inside a shielded spin valve sensor stack. Elements of the matrix can be expressed as fourfold integrals of a scalar Green function. The Green function itself is derived by the method of separation of variables and can be expressed in terms of Fourier series expansions and Fourier integrals. A micromagnetic reader model including the media-to-sensor demagnetization matrix is used to study some aspects of the readback process in perpendicular recording.