The out-of-plane transport properties of the high-$T_c$ oxide compounds, including conductivity, thermoelectric power, and Hall coefficient, are extraordinarily anomalous. In this Rapid Communication, we show that the sign and temperature dependence of these transport coefficients can be explained by a phonon-assisted hopping mechanism of electrons between the neighboring two-dimensional Cu-O planes.

• Received 6 July 1988

DOI:https://doi.org/10.1103/PhysRevB.38.11992