A Study of Linear Density Dependence of Media Noise Power in Perpendicular Magnetic Recording

Abstract

Media noise power saturates at high linear density in perpendicular magnetic recording. It has been reported that one of the root causes is transition noise saturation due to unsaturated magnetization governed by transition width. However, noise saturation phenomena cannot be fully explained by this mechanism alone. For example, low noise media which saturate at lower linear density show better read-write performance. In this study, we show that noise saturation can be explained by a combination of a readback effect and a noise spectrum that changes with density.

Cluster cutting: A better understanding of media noise power and its plateau vs. linear density in perpendicular recording

“…linear density, followed by a plateau ( Figure 1) . Some suggested explanations call for a tenuous balance between transition noise and ac noise or a delicate interplay of magnetics [1][2][3][4][5][6] . One of the earliest models [1] involved a hypothesis that the beginning of the plateau region corresponds to the transition spacing reaching the cluster diameter .…”