Reading process of MR head investigated with micromagnetic model

Perpendicular magnetic recording is a promising candidate for future recording system over 200 Gb/in². Therefore, it is important to have a tool that can prospect accurately a reproduced waveform and roll-off characteristics. Generally, a reciprocity method is used to analytically study a signal waveform in which a fictitious head field is used. In perpendicular magnetic recording, it is difficult to obtain an exact fictitious field due to strong and complicated interaction between MR head and soft underlayer (SUL). Thus, it is desirable to directly calculate reading process with a micromagnetic model considering the MR-SUL interaction. In this study, we investigated the read process in GMR head using a micromagnetic model taking into account the interaction. It was found that the interaction between the shields of MR head and SUL reduces the peak amplitude of signal.