Anisotropic transport properties of PrBa2Cu3O7

The in-plane resitivity is measured on the twin-free PrBa2Cu3O7 crystals. The observal anisotropy indicates that dominant carrier conduction takes place in the CuO one-dimensional chain. By applying the pressure, rho(a), containing CuO2 plane contribution increases more rapidly than rho(b), containing both chain and plane contributions. This is considered to be due to the increased the hybridization between Pr4f and O2p orbital at the plane site, consistent with the scenario proposed by Fehrenbacher and Rice.