Fast switching of magnetic nanoparticles: simulation of thermal noise effects using the Langevin dynamics

Summary form only given. The most straightforward method to simulate fast switching in magnetic systems is the so called Langevin dynamics, where the stochastic equations of motion for magnetic moments are solved. Thermal fluctuations are taken into account using the so called fluctuation (random) field H/sup fl/ which is added to the ´standard´ deterministic effective field H/sup det/. Two important methodical problems do exist when applying this formalism: (i) which interpretation of the stochastic differential equations (Ito or Stratonovich) should be used to obtain physically correct results and (ii) how to chose the correlation properties of the random field H/sup fl/. We address these two issues. We then present simulation results concerning the influence of thermal fluctuations on the fast switching of magnetic nanoparticles.