loading page

in2 Recording Areal Density on Strontium Ferrite Tape
  • +16
  • Mark Lantz ,
  • Simeon Furrer ,
  • Patrick Ebermann ,
  • Hugo Rothuizen ,
  • Walter Haeberle ,
  • Giovanni Cherubini ,
  • Roy D. Cideciyan ,
  • Shinji Tsujimoto ,
  • Yoshihiro Sawayashiki ,
  • Yuto Murata ,
  • Tomohide Ueyama ,
  • Yoichi Akano ,
  • Tetsuya Kaneko ,
  • Hodaka Suzuki ,
  • Masashi Shirata ,
  • Kenji Naoi ,
  • Takashi Koike ,
  • Hiroaki Doshita ,
  • Noriko Imaoka
Mark Lantz
IBM Research

Corresponding Author:[email protected]

Author Profile
Simeon Furrer
Author Profile
Patrick Ebermann
Author Profile
Hugo Rothuizen
Author Profile
Walter Haeberle
Author Profile
Giovanni Cherubini
Author Profile
Roy D. Cideciyan
Author Profile
Shinji Tsujimoto
Author Profile
Yoshihiro Sawayashiki
Author Profile
Yuto Murata
Author Profile
Tomohide Ueyama
Author Profile
Yoichi Akano
Author Profile
Tetsuya Kaneko
Author Profile
Hodaka Suzuki
Author Profile
Masashi Shirata
Author Profile
Kenji Naoi
Author Profile
Takashi Koike
Author Profile
Hiroaki Doshita
Author Profile
Noriko Imaoka
Author Profile


The recording performance of a new prototype magnetic tape based on perpendicularly oriented strontium ferrite particles is investigated using a 29 nm wide tunneling magnetoresistive reader. At a linear density of 702 kbpi, a post-detection byte-error rate of 2.8e-2 is demonstrated based on measured recording data and a software read channel. The read channel uses a 64-state implementation of an extended version of a data-dependent noise-predictive maximum-likelihood detection scheme that tracks the first and second order statistics of the data-dependent noise. At the demonstrated post-detection byte-error rate, a post-error-correction-coding byte-error rate of less than 1e-20 can be achieved using an iterative decoding architecture. To facilitate aggressive track-density scaling, we made multiple advances in the area of track following. First, we developed a new timing-based servo pattern and implemented a novel quad channel averaging scheme. Second, we developed a new field programmable gate array prototyping platform to enable the implementation of quad channel averaging. Third, we enhanced our low disturbance tape transport with a pair of 20 mm diameter air bearing tape guides and a prototype track-following actuator. Fourth, we developed a novel low friction tape head and finally, we designed a set of tape speed optimized track-following controllers using the model-based H∞ design framework. Combining these technologies, we achieved a position error signal (PES) characterized by a standard deviation ≤ 3.18 nm over a tape speed range of 1.2 to 4.1 m/s. This magnitude of PES in combination with a 29 nm wide reader enables reliable recording at a track width of 56.2 nm corresponding to a track density of 451.9 ktpi, for an equivalent areal density of 317.3 Gb/in2.