"Using only two electrodes to both program and read a memory cell may simplify the construction of the memory cell and simplify the circuitry needed to control operation of a memory.Suitable electrically conductive materials for use as electrodes include metals, metal alloys, metal nitrides, oxides, sulfides, carbon, and polymers, including for example: aluminum (Al), silver (Ag), copper (Cu), tita" . . . . . . .