A theoretical study of nonlinear transition shift

An analytical formula is developed for calculating the magnetostatic field from a longitudinal magnetic transition with a hyperbolic tangent transition shape. This formula is utilized to study the dependence of nonlinear transition shift of a dibit pattern on recording parameters, such as flying height and recording bit density. It is found that at very low densities the nonlinear transition shift varies with bit length B as N(B)~1/B³. The power factor decreases with increasing density and it decreases faster for higher flying height. For practical recording densities, the power ~2. The relation N(B) is then used to determine the optimal write precompensation level theoretically