Nonlinear Transition Shift in Heat Assisted Magnetic Recording

To achieve high linear densities in magnetic recording noise as well as distortions must be reduced. A significant source of distortions is the interaction between consecutive magnetic transitions that produces a nonlinear transition shift (NLTS). Using a heat assisted magnetic recording system we measured the dibit response for pseudo-random bit sequences. We find that the sign of the echo corresponding to first order NLTS is inversed with respect to conventional perpendicular magnetic recording. A simple physical explanation is given for this experimental finding.