Two lifetimes and the pseudogap in the orbital magnetoresistance of Zn-substituted La{1.85}Sr{0.15}CuO{4}

TL;DR

This study investigates how zinc doping affects the magnetoresistance and Hall effect in La{1.85}Sr{0.15}CuO{4}, revealing a consistent proportionality at high temperatures and differences in pseudogap evolution at low temperatures.

Contribution

It demonstrates that the orbital magnetoresistance follows a universal relation with the Hall angle across various zinc doping levels, and highlights how pseudogap behavior varies with doping.

Findings

Orbital magnetoresistance proportional to Hall angle squared at high temperatures.

Proportionality constant remains doping-independent at 13.7.

Different low-temperature behaviors suggest distinct pseudogap evolution.

Abstract

The effect of zinc doping on the anomalous temperature dependence of the magnetoresistance and the Hall effect in the normal state was studied in a series of La{1.85}Sr{0.15}Cu{1-y}Zn{y}O{4} films, with values of y between zero and 0.12. The orbital magnetoresistance at high temperatures is found to be proportional to the square of the tangent of the Hall angle, as predicted by the model of two relaxation rates, for all Zn-doped specimens, including nonsuperconducting films. The proportionality constant is equal to 13.7+/-0.5 independent of doping. This is very different from the behavior observed in underdoped La{2-x}Sr{x}CuO{4} films where a decrease of x destroys the proportionality. In addition, the behavior of the orbital magnetoresistance at low temperatures is found to be different depending on whether x is changed or y. We suggest that these differences reflect a different evolution of the pseudogap in the two cases.