Novel efficient techniques for computer simulation of magnetic recording

Perpendicular recording - a new paradigm for high-density magnetic recording currently under intensive development - presents complex engineering challenges which require that design be assisted by computer simulation. However, simulating perpendicular recording is itself a challenge for several reasons; it requires a large simulation box that includes both write head and hard disk and must be treated at high spatial resolution, and the simulations must run for long periods of time and for numerous data inputs. To accomplish this complex modeling, we have developed novel techniques which involve a mixed real-space/Fourier-space representation and which compute time scales linearly with system size, enabling large simulations to be performed efficiently. We show tests of our methodology and provide an example of a simulation that involves writing three bits (a tribit) to disk.