Violation of the isotropic mean free path approximation for overdoped La2−xSrxCuO4

Magnetotransport measurements on the overdoped cuprate La1.7Sr0.3CuO4 are fitted using the Ong construction [ Phys. Rev. B 43 193 (1991)] and band parameters inferred from angle-resolved photoemission. Within a band picture, the low-temperature Hall data can only be fitted satisfactorily by invoking strong basal-plane anisotropy in the mean free path ℓ. This violation of the isotropic-ℓ approximation supports a picture of dominant small-angle elastic scattering in cuprates due to out-of-plane substitutional disorder. We conjecture that both band anisotropy and anisotropy in the elastic-scattering channel strongly renormalize the Hall coefficient in La2−xSrxCuO4 across the entire overdoped regime.