Longitudinal Magnetic Recording (LMR) is the classic magnetization method of hard disks, which originates from the 1960s and in which the data
is stored horizontally on the hard disk. In the meantime, other processes have been developed
with which thestorage density of hard disks can be significantly increased. Perpendicular Magnetic Recording (PMR), in which the data is stored perpendicular to the magnetic surface, and Shingled Magnetic Recording
(SMR), in which the track positions are optimized, should be mentioned.
In Longitudinal Magnetic Recording, magnetization occurs in the horizontal direction in accordance with the rotation of the hard disk. The magnetic fields of adjacent data bits with opposite magnetization are separated from each other by a transition region. The longitudinal method has been improved over the years and, as far as storage density is concerned, has already exhausted its limits years ago. With this method, storage densities between 100 and 200 Gbit per square inch can be achieved with superparametric effects.