Experimental study of nonlinear transition shift and error rate degradation caused by thermal decay

Abstract

It is demonstrated that the nonlinear transition shift (NLTS) increases with time in a thermally unstable medium. The measurements were performed using an experimental medium with low magnetic moment. The increase of NLTS during thermal decay can be explained by the density dependence of the decay rates. This density dependence of thermal decay rates is caused by demagnetization field from adjacent transitions. A random magnetization pattern demonstrates different amplitude decay at high and low densities, and an increased level of NLTS. Error rates of PRML channel were estimated before and after the thermal decay. © 1999 American Institute of Physics.