Perpendicular recording heads for extremely high density recording

Effects of Head Pole Aspect Ratio and Skew Angle on Areal Density in Perpendicular Recording

“…For a small 5 skew angle, with increasing pole length, the track density increases slightly initially but then decreases slightly. However, when the skew angle continues to increase, a larger pole length decreases the track density due to a larger cross-track fringe field [6]. The decrease is more significant at larger skew angles.…”

“…However, to continuously increase the areal density, head skew angle poses a big challenge [5]. To eliminate the skew effect, a trapezoidal main pole has been used [6]. However, the focused ion beam (FIB) processes become more and more difficult when the head dimensions continue to shrink.…”

Multilevel and Three‐Dimensional Nanomagnetic Recording

“…Therefore, to further extend the areal density, it is necessary to further reduce the grain size and thus further reduce the ratio in Expression 1; this implies stepping in the superparamagnetic limit. The modern laboratory demonstrations indeed indicate that the information becomes highly unstable as the areal density is increased above approximately 200 Gbit/in 2 [27]. That is why the multibillion data storage industry is currently searching for an alternative technology that could extend scaling and thus areal data density much beyond the current limits.…”

“…Temporary Solution/Patch in Layman's Terms. So called perpendicular recording promises to defer the fundamental superparamagnetic limit for several more years [28][29][30][31][32]. Ideally, this could bring the areal densities in demonstration data storage systems to one Tbit-per-square-inch.…”

Target of Transition Jitter and Transition Parameter for Over 200 Gb/in<tex>$^2$</tex>in Perpendicular Magnetic Recording

“…The electronic system noise was assumed to be 30 dB . To understand this calculation's characteristics of perpendicular magnetic recording, data from the 146 Gb/in demo [4] were used as a reference. The transition width and transition jitter of this case were estimated to be about 40 and 2.4 nm, respectively.…”