EXCHANGE ENERGY REPRESENTATIONS IN COMPUTATIONAL MICROMAGNETICS

In order to solve Brown's equations, which describe a continuous mediu m, computational micromagnetic modeling requires a discrete representa tion of the magnetization M(r), and a discrete representation of the d erivatives of M(r) must be chosen. This choice may be made through an explicit choice of interpolation or through the choice of numerical re presentation of Brown's equations. In this paper we describe some alte rnative representations of the exchange energy on a square 2-D grid, a nd test these representations through comparison with analytical resul ts for magnetization spirals and with simulations testing vortex and d omain wall mobility.