Quantum Percolation in Electron Cuprate Superconductors Nd sub (2-x) Ce sub x CuO sub (4-y).

Chemical trends in metallic and superconductive properties of these materials are incompatible with theoretical models based on formal carrier density alone. Defect-assisted quantum percolation explains these trends and identifies the specific defect complex responsible for interlayer electrical currents. Ordering of these specific defect complexes to form superlattice domains explains the anomalously normal magnetoresistance in these reduced n-type materials compared to oxidized p-type cuprate superconductors.