Recording Simulation of Patterned Media Toward 2 Tb/in2

Recording simulation of bit patterned media for recording densities toward 2 Tb/in² was studied. The magnetic dot was modeled as 10 nm long, 15 nm wide, and 5 nm thick with m_s=1000 emu/cm³. The dots were arranged in densities of 1-2 Tb/in² on a soft magnetic underlayer with a 25-nm cross track pitch. A head field of a shielded planar head with a pole size of 14times45 nm² and a head-medium spacing of 6 nm was used. When the switching timing of the head field was properly chosen, a 2 Tb/in² pattern was successfully recorded on a track but the obtained switching window was only 2.5 nm due to increased magnetostatic interaction between the dots. Introduction of the exchange coupling between the neighboring dots by connecting the dots was found to increase the switching window up to 6 nm along with an increase in cross track shift margin