Effects of Island Volume and Hotspot Position Fluctuation for Heated-Dot Magnetic Recording

Heated-dot magnetic recording (HDMR), which employs the laser to heat a bit-patterned medium before recording data, is a promising technology to achieve an ultra-high recording density. Generally, many parameters can cause an error during the writing process in an HDMR system; however, this letter investigates only the effect of bit island volume, bit island position fluctuation, and hotspot position fluctuation. Specifically, three bit island volumes are considered, i.e., 1100, 860, and 620 nm$^{\text{3}}$. In addition, we also study the 3-by-3 data patterns that easily cause an error when the hotspot and write head positions have fluctuated. To achieve an error-free writing process, the heating temperature is studied using the Brillouin function for thermal calculations. Implementation of treating the hotspot and evaluating the thermal effect is explicitly described. Simulation results indicate that the smaller the position variation, the lower the error percentage. Moreover, we found that the error percentage is decreased as the heating temperature is increased. Finally, it is apparent that the smaller the island volume, the lower the error percentage.