METASTABILITY IN THE 2-DIMENSIONAL ISING-MODEL WITH FREE-BOUNDARY CONDITIONS

We investigate metastability in the two dimensional Ising model in a s quare with free boundary conditions at low temperatures. Starting with all spins down in a small positive magnetic field, we show that the e xit From this metastable phase occurs via the nucleation of a critical droplet in one of the four corners of the system. We compute the life time of the metastable phase analytically in the limit T --> 0, h --> 0 and via Monte Carlo simulations at fixed Values of T and h and find good agreement. This system models the effects of boundary domains in magnetic storage systems exiting from a metastable phase when a small external field is applied.