Performance Limitation of Microwave Assisted Magnetic Recording Combined With Exchange Coupled Composite Media Explored by Genetic Algorithm

A simple spin model combined with genetic algorithm showed the performance limitation of microwave assisted magnetic recording (MAMR) with multilayer media (MLM). Designs of MLM and MAMR were optimized so as to maximize the media thermal stability and the response of media magnetization to the external recording field. Tradeoff relationships between the two design objectives showed that higher AC-field is required for MLM than for the case in single-layer media. This is mainly because the condition for obtaining frequency matching between AC field and precession in each layer is difficult to achieve with the exchange coupling composite effect.