Affects of skew angle on the written-in base line shift (BLS) signal at high track densities

The track edge charge distribution responsible for the base line shift (BLS) in the MR readback waveform is studied through skew angle measurements. A model based on a finite element head field calculation and micromagnetic simulation is utilized to understand the track edge charge formation responsible for the BLS signal. The modeling results show that the spatial distribution of the dipole charge profile in the cross track direction becomes asymmetric when transitions are written at skew angles. This explains the observed asymmetry in the measured base line shift profile