Writing and detecting bits at 100 Gbit/in² in longitudinal magnetic recording media

We have written bits in longitudinal media at extremely high areal densities, >100, using a focused ion beam (FIB) trimmed write head mounted on a static write/read tester. Bits were written at a track pitch of ∼100 nm and with a 62.5 transition spacing with the same trimmed write head. The bits were characterized with the head read sensor and also with magnetic force microscopy (MFM). The MFM images were analyzed with respect to transition position jitter, signal-to-noise, and track width.