On Monday, Ondrej Hovorka, a Lecturer in Computational Modelling at the University of Southampton, gave an overview of modern magnetic recording technology and the challenges faced by industry, such as Seagate and Hitachi/Western Digital, and academia in developing it further.
Starting with the current generation technology of Perpendicular Magnetic Recording (PMR), he outlined the basic physics of how bit information is stored in the grains of the FePt magnetic disk. Because the coercive field required to write information to this disk depends on both the size of the grains and fundamental properties of the material, then without the discovery of a more practical material, this technology is reaching its limitations.
PMR and HAMR comparison (from Seagate)
Moving onto the next proposed technology, which is an adaptation of PMR that would require little change on the part of the developers, he showed the proposed set up of Heat Assisted Magnetic Recording (HAMR). By using the thermal properties of the material and heating it with a laser just before writing to make writing easier. This could allow for up to 4x the areal density on magnetic hard disks but presents many academic challenges to succeed. Research into many properties of the grains must be done and require both dynamical and Monte Carlo simulation in order to find both long and short timescale behaviour.
Posted by Jonathon Waters