Data Rate Effects on Transition and Remanence Noise in a Modeled Heat-Assisted Magnetic Recording System

Abstract

The heat-assisted magnetic recording performance at varying data rate conditions is investigated using an ensemble waveform analysis method. This method decouples the transition signal-to-noise ratio (SNR) and the remanence SNR from the total spatial media SNR. For data rates below 2200 Mbpsi, transition and remanence noises are largely independent of writer field rise time (RT) values less than 150 ps. Above a data rate of 2200 Mbpsi, the transition SNR is significantly degraded for the slowest RTs considered. For all data rate values, the remanence SNR sees minimal degradation with increasing RT. At the highest data rate, at least a 1 dB loss is observed compared with the lowest data rate, across the RT range considered. For comparison, spin-stand data were also collected. The modeled results were contrasted to bit error rate (BER) trends obtained from the measurement. The spin-stand data show a significant BER degradation as a function of increasing RT at higher data rates. This trend is likely explained with the increase in transition noise observed in the model. These results suggest that moderate writer field RTs do not degrade either transition or remanence noise significantly. If RTs can be kept low, higher data rates may be allowable from a media noise perspective.