1 M ay 1 99 8 Switching dynamics between metastable ordered magnetic state and nonmagnetic ground state - A possible mechanism for

By studying the dynamics of the metastable magnetization of a statistical mechanical model we propose a switching mechanism of photoinduced magnetization. The equilibrium and nonequilibrium properties of the Blume-Capel (BC) model, which is a typical model exhibiting metastability, are studied by mean field theory and Monte Carlo simulation. We demonstrate reversible changes of magnetization in a sequence of changes of system parameters, which would model the reversible photoinduced magnetization. Implications of the calculated results are discussed in relation to the recent experimental results for prussian blue analogs. Typeset using REVTEX