Fujitsu, partner aim for terabit disk density

Perpendicular recording techniques promise to more than double density capabilities in the next few years, increasing from the 200Gbits per square-inch that longitudinal recording techniques pack today to as high as 500Gbits per square-inch.

Fujitsu Laboratories Ltd proposes that to double density again, to the terabit-per-square-inch domain, researchers add nanoscale patterns to preformat the location of bit cells in perpendicular media. This is a capability it demonstrated recently in cooperation with Kanagawa Academy of Science and Technology, also based in Japan.

Fujitsu and Kanagawa Academy recently showed a prototype of what they described as the world's first alumina nanohole-patterned media, which could be validated with a flying head read/write operation on a 2.5-inch magnetic disk. The aligned alumina nanohole patterns used a 100nm pitch by virtue of nanoimprint lithography. The resulting patterned bit cells could be isolated for reading and writing with existing read heads. Next Fujitsu plans to test its media with the nanoholes cranked down to a pitch of 25nm¡ªthe density required to reach its ultimate goal of one-terabit-per-square-inch densities. The media has already been fabricated, Fujitsu says, but a new type of trailing shield head that is not yet available will be needed to read and write to the terabit-per-square-inch media.