8- ${\rm Tb/\in}^{2}$ -Class Bit-Patterned Medium for Thermally Assisted Magnetic Recording

Three-dimensional optical/thermal spot profiles obtained by thermally assisted magnetic recording (TAMR) on bit-patterned media (BPM) with dot densities of 6 to 15 Tb/in² were numerically analyzed. Introduction of a spacing layer with higher thermal conductivity than that of the recording dots leads to narrow temperature distribution (i.e., steep temperature profile) in the dots. A temperature profile with FWHM of less than 5 nm was obtained on a patterned dot array under areal densities of 6 to 15 Tb/in². In addition, introduction of a thermal-control layer beneath the recording layer decreased vertical temperature difference within a recording bit while keeping a narrow temperature distribution. Feasibility of 8-Tb/in²-class TAMR on a BPM was verified by LLG simulation with a triangular antenna-type near-field optical element.