Optimization of magnetic read widths in two dimensional magnetic recording based on micromagnetic simulations

Optimization of magnetic read widths (MRWs) and reader positioning in two dimensional magnetic recording (TDMR) are explored. The optimization is based on waveforms from 511-bit maximal-length pseudo-random binary sequence (PRBS) patterns. The TDMR error rates are determined from a large ensemble of full micromagnetic simulations. Each simulation involves writing three overlapping tracks in a shingled magnetic recording (SMR) configuration. Two readers, separated by a specified offset, are used to read the written patterns, and the waveform from each reader is equalized. Then, the two equalized waveforms are combined and the combined waveform is re-equalized for the channel detection. Initially, identical MRWs for the two readers are considered, and the best reader offset is found in order to achieve the largest areal density (AD) gain. A unique aspect of this work is that multiple MRWs can be analyzed and shown to further enhance the AD gain. A software channel, capable of treating both experimental data and simulation output with the same methodology, is used to quantify the TDMR gain and to analyze the contribution of each noise source to the results.