Feasibility of bit patterned media for HAMR at 5 Tb/in²

We have investigated the feasibility of BPM for HAMR via Finite Difference Time Domain and atomistic simulation and we have substantiated the feasibility of 5 Tb/in² with two filling factors 25% and 56% even when the maximum on-track bit temperature is below the Curie temperature. The success of this underheated switching is attributed to sufficiently low anisotropy instead of reduction of Curie temperature. The temperature gradient in the cross-track direction is almost doubled if the optical head width is reduced by half, indicating the possibility of higher areal densities. Moreover, contrary to continuous media, we also found that the power absorption peaks at the bottom of the bit patterned FePt when the media is illuminated from above, which is probably due to stronger coupling there between FePt and the surrounding materials.