Physics of Perpendicular Recording: Effects of Magnetic 'Charges'

Using a 3D expression for the stray field emanating from a perpendicular medium with information recorded at different areal densities, the effects of the magnetic ?charge? distribution were explored. The existence of a peak in a density roll-off curve is one of the typically observed effects in perpendicular recording. Comparison between longitudinal and perpendicular recording technologies was made, and guidelines helping appropriately choose the bit aspect ratio (BAR), the recording layer thicknesses, and other parameters, were derived.