Abstract
The field-induced switching of conductance in the charge ordered half-doped manganites is controlled by the combination of metastability, an inhomogeneous high-field state, and cation disorder. We study this non-equilibrium problem via real space Monte Carlo on a disordered strong coupling model appropriate to the manganites. We reproduce the variation of the switching fields with the mean ionic radius rA and cation disorder σA, and demonstrate how the experimental features arise from the proximity of several phases in the Landau free-energy landscape. Our prediction for the field melted state is consistent with a growing body of experimental evidence.