Mechanism for electric field effects observed in YBa2Cu3O7−x films

Abstract

The chain oxygen dynamics of ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{7\mathrm{-}\mathit{x}}$ have been investigated using a Monte Carlo simulation of the asymmetric next-nearest-neighbor Ising model for the oxygen atoms in the basal plane. The effect of an electric field is to change the basal plane coordination of Cu ions, resulting in a change in the carrier doping of the ${\mathrm{CuO}}_2$ planes. The ratio of magnitudes of the changes in the doping under potentials of +10 V and -10 V is in good agreement in magnitude and sign with that observed in field effect experiments, as are also the time constants for the resistance changes.