Scaling behavior of the conductivity of Nd2CuO4-x- delta Fx single crystals: Evidence for orthogonal symmetry.

Abstract

We have measured electrical conductances for single-crystal ${\mathrm{Nd}}_{2}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathit{x}\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$${\mathrm{F}}_{\mathit{x}}$ samples by changing the parameters x(=0.02--0.30) and \ensuremath{\delta}. We confirm that observed conductances can be unifiedly described by a single \ensuremath{\beta} function from the weakly to the strongly localized regime. We claim, from our analysis of the data using the \ensuremath{\beta} function, that the nonsuperconducting state of ${\mathrm{Nd}}_{2}$${\mathrm{CuO}}_{4\mathrm{\ensuremath{-}}\mathit{x}\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}$${\mathrm{F}}_{\mathit{x}}$ systems is the two-dimensional Fermi-liquid system described by orthogonal symmetry.