Erase Band Noise and Generation Mechanism Due to an Adjacent Track

In this paper, the erase band generation mechanism is discussed focusing on both the magnetic field from background tracks and variation in medium microstructure as origins of erase bands. The edge positions of bits in an overwrite track was examined. According to the same principle as the easy/hard transition shift, magnetostatic interference from the background track is also likely to shift the edge position of overwrite track in the cross-track direction and these shifts result in a clear broadening of the erase band. Erase band widths measured for various linear densities of background and overwrite tracks verified the proposed mechanism qualitatively and the largest noise, corresponding to AC erased noise, emanated from easy edges according to numerical calculations.