Hitachi shows perpendicular recording density to 610Gb / square inch is possible


Per­pen­dic­u­lar record­ing (or Per­pen­dic­u­lar Mag­net­ic Record­ing, PMR) is a recent­ly imple­ment­ed tech­nol­o­gy for data record­ing on hard disk

The main chal­lenge in design­ing mag­net­ic infor­ma­tion stor­age media is to retain the mag­ne­ti­za­tion of the medi­um despite ther­mal fluc­tu­a­tions caused by the super­para­mag­net­ic lim­it. If the ther­mal ener­gy is too high, there may be enough ener­gy to reverse the mag­ne­ti­za­tion in a region of the medi­um, destroy­ing the data stored there. The ener­gy required to reverse the mag­ne­ti­za­tion of a mag­net­ic region is pro­por­tion­al to the size of the mag­net­ic region and the mag­net­ic coer­civ­i­ty of the mate­r­i­al. The larg­er the mag­net­ic region is and the high­er the mag­net­ic coer­civ­i­ty of the mate­r­i­al, the more sta­ble the medi­um is. There is a min­i­mum size for a mag­net­ic region at a giv­en tem­per­a­ture and coer­civ­i­ty. If it is any small­er it is like­ly to be spon­ta­neous­ly de-mag­ne­tized by local ther­mal fluc­tu­a­tions. Per­pen­dic­u­lar record­ing uses high­er coer­civ­i­ty mate­r­i­al because the head­’s write field pen­e­trates the medi­um more effi­cient­ly in the per­pen­dic­u­lar geom­e­try.” — Wikipedia

Hitachi, Ltd. is work­ing on per­pen­dic­u­lar record­ing tech­nol­o­gy and made improve­ments to it. Final­ly on 31st, July 2008, Announced that the max­i­mum stor­age den­si­ty pos­si­ble is 610 Gb/​square inch. This is far bet­ter than cur­rent tech­nique. It leads 2.5x times HDD capac­i­ties that are cur­rent­ly avail­able. This tech­nique also shows the evi­dence that hard dri­ve capac­i­ties have the poten­tial to advance at a rate of 40% annually.

These results are based on many years of expe­ri­ence with design opti­miza­tion and mate­r­i­al tech­nol­o­gy for per­pen­dic­u­lar record­ing heads and media. We applied this knowl­edge to the devel­op­ment of heads and media with an ultra-nar­row track pitch of 65nm, indis­pens­able in achiev­ing a record­ing den­si­ty of 610 Gbit/​in2. Devel­op­ment of iter­a­tive sig­nal pro­cess­ing tech­nol­o­gy for high den­si­ty record­ing fur­ther increased den­si­ty and capac­i­ty,” said Hiroa­ki Odawara, Research Direc­tor, Stor­age Tech­nol­o­gy Research Cen­ter, Cen­tral Research Lab­o­ra­to­ry, Hitachi, Ltd.

Hitachi GST demon­strat­ed 230 Gbit/​square inch. in April 2005, 345 Gbit/​square inch. in Sep­tem­ber 2006, and has now shown extend­abil­i­ty to 610 Gbit/​square inch. These new meth­ods are still being devel­oped, but hold poten­tial for much greater advance­ments in are­al den­si­ty growth.

Read more at Physorg