123 Gbit/in2 Recording Areal Density on Barium Ferrite Tape

• Published in: IEEE transactions on magnetics Vol. 51; no. 11; pp. 1 - 4
• Main Authors: Lantz, Mark A., Furrer, Simeon, Engelen, Johan B. C., Pantazi, Angeliki, Rothuizen, Hugo E., Cideciyan, Roy D., Cherubini, Giovanni, Haeberle, Walter, Jelitto, Jens, Eleftheriou, Evangelos, Oyanagi, Masahito, Morooka, Atsushi, Mori, Masahiko, Kurihashi, Yuichi, Kaneko, Tetsuya, Tada, Toshio, Suzuki, Hiroyuki, Harasawa, Takeshi, Shimizu, Osamu, Ohtsu, Hiroki, Noguchi, Hitoshi
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; Detectors; Magnetic heads; magnetic recording; Magnetic tape; magnetic tape recording; Magnetism; Media; Optical variables measurement; Servomotors; signal detection; Signal to noise ratio; tracking; signal detection; magnetic tape recording; tracking; Magnetic recording
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2015.2435893

The recording performance of a prototype magnetic tape based on perpendicularly oriented barium ferrite particles is investigated using an enhanced field tape write head and a 90 nm wide giant-magnetoresistive reader. A linear density of 680 kbits/in with a postdetection byte-error rate (BER) <;3.2e-2 is demonstrated based on recorded data processed by a software read channel with noise-predictive maximum likelihood detection. With this detector error rate, a user BER of <;1e-20 can be achieved by means of product error correction coding and iterative decoding. Several advances in the area of track-following servo control are also presented. Specifically, we describe a new timing-based servo pattern, which in combination with an optimized servo channel enables the generation of position estimates with nanoscale resolution and a high update rate. Track-following experiments are performed using an experimental low-noise tape transport, a prototype high-bandwidth actuator, and a set of speed-optimized H-infinity-based track-following controllers. Combining these technologies, we demonstrate a position-error signal (PES) with a standard deviation of 5.9 nm or less over a tape speed range of 1.23-4.08 m/s. This magnitude of PES in combination with a 90 nm wide reader allows operation with 140 nm wide tracks. Combined with a linear density of 680 kbits/in, this leads to an equivalent areal density of 123 Gbits/in 2 .