垂直磁気記録のエラーレートにおける波形パラメータ依存性の検討

Abstract

In perpendicular magnetic recording, the major concerns are transition position jitter, which is the dominant noise source, and magnetization transition width or transition parameter, which affects readback pulse width. Thus, these parameters restrict attainable linear density. Their influence on error rate performance was investigated with numerically synthesized waveforms and a software channel. Calculated error rate shows that transition jitter restricts the bit error rate (BER) for small pulse widths. However, when the pulse is wide, it causes BER degradation by system noise emphasis during equalization. Assuming a target density of 200 Gb/in2, with linear density of 1200 kFCI, a transition jitter of 1.6 nm and transition parameter of 20 nm are a compromise. In this case, 2% resolution is estimated at the linear density of 1200 kFCI for a read gap of 60 nm and magnetic spacing of 15 nm.