Areal density optimizations for heat-assisted-magnetic recording of high density bit-patterned media

摘要

Heat-assisted-magnetic recording (HAMR) is hoped to be the future recordingtechnique for high density storage devices. Nevertheless, there exist severalrealizations strategies. With a coarse-grained Landau-Lifshitz-Bloch (LLB)model we investigate in detail benefits and disadvantages of continuous andpulsed laser spot recording of shingled and conventional bit-patterned media.Additionally we compare single phase grains and bits having a bilayer structurewith graded Curie temperature, consisting of a hard magnetic layer with high$T_{\mathrm{C}}$ and a soft magnetic one with low $T_{\mathrm{C}}$,respectively. To describe the whole write process as realistic as possible adistribution of the grain sizes and Curie temperatures, a displacement jitterof the head and the bit positions are considered. For all these cases wecalculate bit error rates of various grain patterns, temperatures and writehead positions to optimize the achievable areal storage density. Within ouranalysis shingled HAMR with a continuous laser pulse moving over the mediumreaches the best results, and thus having the highest potential to become thenext generation storage device.