Rotated read head design for high-density heat-assisted shingled magnetic recording

In heat-assisted shingled magnetic recording, recorded tracks are erased on one side. The transitions are no longer symmetric relative to the track center, especially when the transitions are highly curved as a result of the temperature profile generated by the near-field transducer. To optimally utilize these asymmetrically curved transitions, the read head is rotated to match the curvature. For a single rotated head, a more than 10% improvement in user density is achieved compared to that of a single non-rotated head. We found that the optimal rotation angle generally follows the transition shape. With an array of two rotated heads, a track pitch of 15 nm, and a minimum bit length of 6.0 nm, the user areal density reaches 6.2 Tb/in2, more than 30% above previous projections for recording on granular media.