A Study of Ultra-High Linear Density Recording of Perpendicular Magnetic Recording

Partial response channels, which recently have been applied to high-density recording, have a design based on linear channels. Since the high linear density signals of perpendicular magnetic recording are well represented as superpositioned isolated pulses, PR methods are suitable for use in perpendicular magnetic recording. Although we have found that superposition is not strictly valid at densities above 100 kFRPI, a newly developed "bilayered main-pole" type head is effective for remedying this problem. As a result, we have achieved data reading/writing at 200 kFRPI with an error rate of 10^¿7.