Abstract
Because conventional perpendicular recording is now reaching its useful limits, the hard drive industry is heavily invested inseveral alternative recording technologies.   The majority of these configurations (such as heat-assisted magnetic recording, microwave-assisted magnetic recording, and bit-patterned magnetic recording) secure their advantages by solving essential problems in the writing process.  In contrast, two-dimensional magnetic recording (TDMR) expends its essential focus on the reading process, by providing multiple looks at adjacent written information via multiple read sensors on one slider.   This “sleeper” technique was rather abruptly recognized, at a recent conference of recording technologists, as a leading contender for the next generation of HDD technology.While generally thought of as a more conventional option than the alternatives, TDMR nevertheless has profound impact on magnetic component design and on elements of the entire supporting recording system.   These impacts will be reviewed in detail from both a magnetic system and a signal-processing perspective.  Innovations in linear and nonlinear system identification techniques in two dimensions will be proposed and illustrated.

CV
Jonathan Coker is a champion of innovative recording technologies that improve the performance, efficiency, and areal density of hard-disk drives (HDDs).   As HGST’s Chief Architect for HDDs, Coker plays a leading role in HGST’sshingled and two-dimensional recording technology efforts.Coker was educated at Wheaton College (B.A., Liberal Arts and Engineering, 1986) and at the University of Minnesota (B.S.E.E., 1984; M.S.E.E, 2006; E.E.Ph.D., 2008).Coker began his career in 1984 at IBM, where he made key contributions to the development and integration of such industry firsts as thin-film disks, magneto-resistive heads, and partial-response, maximum-likelihood data channels. During 2001-7, Coker was a supervising researcher at the Mayo Clinic, working on advanced circuit architectures and implementations for medical and defense-related applications.Dr. Coker is a frequent guest lecturer at industry gatherings and seminars. He holds about 50 patents in the areas of magnetic recording, radar devices and medical applications. Jon has written 22 journal articles or conference papers.