Electron-electron interaction dominated quantum transport in thick CuGe films

Abstract

We have successfully made a series of thick CuxGe100-x films spanning the weakly and strongly localized regimes. With decreasing mole concentration of Cu relative to Ge, the resistivity of film becomes bigger at a given temperature and demonstrates a stronger temperature dependence at low temperatures. When x is big, 46 less than or equal to x less than or equal to 56, resistivity increases with the square root of the decreasing temperature, implying a weak-disorder behavior. For x small, 14 less than or equal to x less than or equal to 2.0, resistivity increases exponentially with decreasing temperature, implying a strongly localized behavior. The results show that the low-temperature transport in these films is dominated by the disorder enhanced electron-electron interaction effects. (C) 2000 Elsevier Science B.V. All rights reserved.