4–5 Tb/in$^{{{2}}}$ Heat-Assisted Magnetic Recording by Short-Pulse Laser Heating

Abstract

Due to poor thermal performance of media, it is difficult for heat-assisted magnetic recording (HAMR) to achieve densities greater than 3 Tb/in $^{ { {2}}}$ for continuous-wave laser heating. Short-pulse laser heating is an attractive approach to improve the thermal response of media. In this paper, the recording performances of HAMR using short-pulse laser heating are studied by dynamic micromagnetic simulations solving the Landau–Lifshitz–Bloch equation. The results show that the magnetic damping constant of the media, $\alpha $ , and applied magnetic field, $H$ , exhibit significant effects on recording quality at a pulse-width of 100 ps. From analyses of the relationships among readout signal and noise ratio, recorded track width, $\alpha $ , and $H$ , the required parameter setting for various recording densities are obtained. It is indicated that with a transducer tip size of 15 nm and heating laser pulse-width of 100 ps, a recording density greater than 4 Tb/in $^{2}$ is achievable for FePt recording media.