Violation of the isotropic-$\ell$ approximation in overdoped La_{2-x}Sr_xCuO_4

TL;DR

This study reveals that in overdoped La_{2-x}Sr_xCuO_4, the isotropic-$ ext{ell}$ approximation fails due to strong basal-plane anisotropy and small-angle elastic scattering, significantly affecting the Hall coefficient.

Contribution

It demonstrates the necessity of considering anisotropic mean-free-path and elastic scattering in modeling magnetotransport in overdoped cuprates.

Findings

Strong basal-plane anisotropy in mean-free-path is required to fit Hall data.

Band anisotropy and scattering anisotropy significantly influence the Hall coefficient.

Violation of isotropic-$ ext{ell}$ approximation supports small-angle elastic scattering dominance.

Abstract

Magnetotransport measurements on the overdoped cuprate La_{1.7}Sr_{0.3}CuO_4 are fitted using the Ong construction 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 $\ell$. This violation of the isotropic-$\ell$ approximation supports a picture of dominant small-angle elastic scattering in cuprates due to out-of-plane substitutional disorder. We show that both band anisotropy and anisotropy in the elastic scattering channel strongly renormalize the Hall coefficient in overdoped La_{2-x}Sr_xCuO_4 over a wide doping and temperature range.