Effect of head field gradient on transition jitter in perpendicular magnetic recording

Noise of perpendicular double-layered media was investigated in connection with write head field of single pole heads. Time-domain noise measurement revealed that the noise was spatially concentrated around transitions, caused by transition jitter. The influence of writing head field was discussed based on jitter measurement using various heads; a ring head and single pole heads. The amount of transition jitter was inversely proportional to estimated writing head field gradient. The writing head field improvement, thus, contributed to reduce the medium noise