Abstract: Provided in one example is a nonvolatile memory crossbar array. The array includes a number of junctions formed by a number of row lines intersecting a number of column lines; and a resistive memory element in series with a selector at each of the junctions coupling between one of the row lines and one of the column lines. The selector may be a volatile switch including: a bottom electrode; an oxide layer disposed over the bottom electrode, the oxide layer including Cu2O; and a top electrode disposed over the oxide layer.