MECHANISM FOR ELECTRIC-FIELD EFFECTS OBSERVED IN YBA2CU3O7-X FILMS

The chain oxygen dynamics of YBa2Cu3O7-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 elect ric field is to change the basal plane coordination of Cu ions, result ing in a change in the carrier doping of the CuO2 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 i n field effect experiments, as are also the time constants for the res istance changes.