Required conditions for the magnetic domain control of narrow-track read heads to achieve high sensitivity and good stability

We found a relationship between the linearity of the transfer curve in read heads and the instability parameter M_x that is determined by the magnetization direction in the free layer at the edge region using a Landau-Lifshitz-Gilbert equation. To develop read heads with a. linear transfer curve, which leads to a stable playback signal, M_x must be larger than 0.9. Using this parameter, we showed the possibility of developing read heads with good stability and high sensitivity. Keeping the magnetic domain control field intensity at the track edge, as well as idealizing its distribution, enabled high sensitivity to be achieved while maintaining good stability.