The interchain resistivity of ${\mathrm{P}\mathrm{r}\mathrm{B}\mathrm{a}}_2{\mathrm{C}\mathrm{u}}_4{\mathrm{O}}_{\mathrm{8}}$ has been measured in high magnetic fields up to 30 T. Coherent interchain transport at low temperatures is destroyed by a large magnetic field applied perpendicular to the CuO chains. Comparisons with quasiclassical transport theory provide strong experimental support for a three-dimensional Fermi-liquid ground state in ${\mathrm{P}\mathrm{r}\mathrm{B}\mathrm{a}}_2{\mathrm{C}\mathrm{u}}_4{\mathrm{O}}_{\mathrm{8}}$, despite extreme anisotropy in its electronic properties and the presence of strong electron correlations.

• Received 20 November 2001

DOI:https://doi.org/10.1103/PhysRevLett.89.086601