Tracking anisotropic scattering in overdoped Tl$_2$Ba$_2$CuO$_{6+\delta}$ above 100 K

TL;DR

This study presents detailed polar angle-dependent magnetoresistance measurements in overdoped Tl$_2$Ba$_2$CuO$_{6+eta}$, revealing complex temperature and momentum-dependent scattering behaviors that challenge existing theories of high-temperature superconductors.

Contribution

It provides expanded and refined measurements of scattering rates, including anisotropic components, up to 100 K, constraining theoretical models of charge response in cuprates.

Findings

Identification of anisotropic $T^2$ scattering component.

Persistence of $T$-linear and $T^2$ components up to 100 K.

Enhanced understanding of scattering anisotropy in overdoped cuprates.

Abstract

This article describes new polar angle-dependent magnetoresistance (ADMR) measurements in the overdoped cuprate Tl$_2$Ba$_2$CuO$_{6+\delta}$ over an expanded range of temperatures and azimuthal angles. These detailed measurements re-affirm the analysis of earlier data taken over a more restricted temperature range and at a single azimuthal orientation, in particular the delineation of the intraplane scattering rate into isotropic and anisotropic components. These new measurements also reveal additional features in the temperature and momentum dependence of the scattering rate, including anisotropy in the $T^2$ component and the preservation of both the $T$-linear and $T^2$ components up to 100 K. The resultant form of the scattering rate places firm constraints on the development of any forthcoming theoretical framework for the normal state charge response of high temperature superconducting cuprates.