Keywords:Monte Carlo simulation, algorithm, ferromagnet
Magnetic behavior of ferromagnets is one of centers of spintronics and magnetics, not only for its theoretical significance, but also for the sake of application. Although the simulation of magnetic property is meaningful, it faces two main challenges: colossal numbers of molecules and complicated long-range interaction. Fast multipole method (FMM) accelerates the calculation of long-range forces in many-body system by dividing remote molecules into grains. Ferromagnetism ensures that neighbouring molecules share almost parallel spin direction. Stochastic cutoff (SCO) algorithm is a newly developed Monte Carlo method to reduce the numbers of bonds between molecules in simulation. I will introduce recent work is to combine these two algorithms to speed up the simulation of magnetic behaviors of ferromagnetic behaviors. This new approach provides a powerful tool for the prediction and design of ferromagnetic devices.