Non-Universal Power Law of the "Hall Scattering Rate" in a Single-Layer Cuprate Bi_{2}Sr_{2-x}La_{x}CuO_{6}

TL;DR

This study investigates the temperature dependence of the Hall angle and magnetoresistance in Bi_{2}Sr_{2-x}La_{x}CuO_{6} crystals, revealing non-universal power-law behavior and the influence of spin scattering across doping levels.

Contribution

It demonstrates that the Hall scattering rate's temperature dependence varies systematically with doping, challenging the assumed universality of T^2 behavior in cuprates.

Findings

Hall angle follows a power law T^n with n decreasing as doping increases.

Optimally-doped samples show Hall angle ~ T^{1.7}, not T^2.

Magnetoresistance indicates increased spin scattering in underdoped samples.

Abstract

In-plane resistivity \rho_{ab}, Hall coefficient, and magnetoresistance (MR) are measured in a series of high-quality Bi_{2}Sr_{2-x}La_{x}CuO_{6} crystals with various carrier concentrations, from underdope to overdope. Our crystals show the highest T_c (33 K) and the smallest residual resistivity ever reported for Bi-2201 at optimum doping. It is found that the temperature dependence of the Hall angle obeys a power law T^n with n systematically decreasing with increasing doping, which questions the universality of the Fermi-liquid-like T^2 dependence of the "Hall scattering rate". In particular, the Hall angle of the optimally-doped sample changes as T^{1.7}, not as T^2, while \rho_{ab} shows a good T-linear behavior. The systematics of the MR indicates an increasing role of spin scattering in underdoped samples.