New concepts for perpendicular magnetic recording hard disk system

Novel concepts for perpendicular magnetic recording are proposed. Recording mechanism analysis, head-to-media interface, and a narrow track single-pole head are described. A finite-element method simulation, with accurate medium modeling, estimates densities over 20 kFRPM (500 kFRPI). The conditions to attain high linear density are revealed quantitatively. Coercive force dispersion of the medium and head-to-medium spacing are key factors. To realize extremely narrow spacing, the authors propose contact recording, that is, a non-flying head even for bard disk systems. Using this head-to-medium interface, a very narrow track single-pole can be prepared with control of the domain structure by a wall pinning method. It was found that the normalized output increases as the track width decreases. The signal-to-noise ratio of a 6-μm-track-width single-pole head is about 35 dB at low density. The 10^-9 error rate was obtained at 4 kFRPM (100 kFRPI) with an equalizer for the read channel