A new kind of non-linear distortion in hard disk drives

This paper introduces a form of non-linear distortion (NLD) in rotating magnetic storage. This NLD is inherent to the read back process, and is caused by a non-linear field versus amplitude response in the read element. This is different than traditional NLD inherent to the write process, or non-linear “saturation” effects in the read back process. Because of these differences, standard methods of mitigating NLD performance losses do not work on magneto-resistive non-linear distortion (MR-NLD). As of today there is no method of mitigating performance losses due to MR-NLD in any shipping hard drive.