Micromagnetic analysis of recording processes in periodic antidot arrays: Interaction between adjacent bits

Lithographically defined nonmagnetic structures in thin magnetic films have been proposed as future ultrahigh density storage systems. Previous investigations by our group have shown that these periodic antidot arrays present adequate remanent states for storage. The optimization of material parameters and geometrical dimensions led to maximum areal densities in the order of 750 Gbits/in.2 for materials with exchange lengths in the range of 3 nm. In this work recording processes are computed. Single bit switching is analyzed by micromagnetic simulations. It is observed how the dipolar and exchange interactions between adjacent bits play a key role. If the applied field is not carefully controlled or the magnetocrystalline anisotropy interaction is not strong enough, the switching of one bit can produce undesired switching of neighboring bits.