Thermal stability on hard disk media beyond 10-20 GBit/Inch

We try to quantitatively estimate at which areal density thermal effects impose a limit to further increase of recording density. The discussion above illustrates that SNR and thermal stability have to be traded off against one another. Therefore, the discussion must combine noise considerations with the theory of thermally activated magnetization reversal. The noise performance is analyzed using a more elaborated approach of recent transition jitter models while the thermally activated magnetization reversal is described by an Arrhenius Nee1 magnetization decay formalism. The considerations illustrate that, for practical media designs, SNR has to be compromised with thermal stability for areal densities roughly beyond 30 Gbit/inch² (longitudinal recording). The number depends on details of the system design.