PHYSICALLY-BASED INFORMATION-SCIENCE OF MAGNETIC RECORDING .1. INFORMATION CAPACITY OF A MEDIUM MODEL

The data processing inequality of information theory states that no re cording system using a medium can achieve a capacity greater than the capacity of the medium itself. We describe an efficient method for det ermining the storage capacity of a magnetic storage medium. We apply t he method to a medium model consisting of a tessellation of magnetic ' 'grains'' and obtain a numerical measure of the storage capacity. We f ind that intergranular dipolar and exchange interactions reduce the st orage capacity below that of a tesselation of non-interacting grains.