Investigations of perpendicular write head design for 1 Tb/in2

We have revisited the considerations of perpendicular recording at 1 Tb/in². We have extensively modeled head designs with the down-track shield (DS) and head designs with the down-track and side shields (DS-SS). The side shields are needed to reduce the thermal erase width, however, there is a substantial reduction in effective write field for the DS-SS heads compared to the DS heads. This reduction in effective write field defines an upper limit for the anisotropy of the medium that can be written. As a consequence, it is hard to simultaneously achieve writability and the thermal stability requirement for 1 Tb/in².