Two-Dimensional Weak Localization in Electron High-T_c Superconductor Nd_2−xCe_xCuO_y under High Magnetic Field

Abstract

Electron high-T_c superconductor Nd_2−xCe_xCuO_y single crystals are studied under high magnetic field of up to 20 tesla. The superconducting state is completely destroyed by the field when the field is applied along the c-axis and the normal electrical resistivity is obtained at all temperatures. The temperature dependence of the normal resistivity is plotted down to 1.3 K and a clear resistance minimum is found. The result is understood in terms of the two-dimensional weak localization model and this means that the materials are regarded as the intrinsic two-dimensional conduction system.