Perpendicular recording near 100 Gb/in/sup 2/

Theoretical analyses have projected perpendicular recording capable of achieving ultimate areal densities greater than longitudinal recording systems. For perpendicular recording to supplant longitudinal recording, laboratory demonstrations will need to be made which intercept or exceed the areal densities achieved by state-of-the-art longitudinal recording demonstrations. Recent demonstrations have come close to eliminating the gap between these technologies. In this paper, recording experiments at areal densities in the 60 to 100 Gb/in/sup 2/ range will be described. It will be shown that the head field from conventional single-pole writers is not well localized to the data track and that if the media do not have sufficiently high nucleation thresholds, this fringe field will gradually erase data on the adjacent track if the track pitch is too aggressive. Extension of this technology to densities of the order of 1 Tb/in/sup 2/ will require heads that reduce the extent of the fringe field without sacrificing available on-track field.