  Thermal collapse of an isolated skyrmion on a two-dimensional spin lattice
has been investigated. The method is based upon solution of the system of
stochastic Landau-Lifshitz-Gilbert equations for up $10^4$ spins. Recently
developed pulse-noise algorithm has been used for the stochastic component of
the equations. The collapse rate follows the Arrhenius law. Analytical formulas
derived within a continuous spin-field model support numerically-obtained
values of the energy barrier and the pre-exponential factor, and their
dependence on the magnetic field. Our findings agree with experiments, as well
as with recent numerical results obtained by other methods.
