1. A nonvolatile memory element, comprising: a first electrode layer; a first variable resistance layer disposed over the first electrode layer; a first layer disposed on the first variable resistance layer; a second variable resistance layer disposed on the first layer; and a second electrode layer disposed over the second variable resistance layer, wherein: the first variable resistance layer and first layer each comprise a first chemical element and a second chemical element; and the stoichiometry of the first and second chemical elements in the first variable resistance layer is different than the stoichiometry of the first and second chemical elements in the first layer.