On the temperature scaling behaviour of the linear magnetoresistance observed in high-temperature superconductors

TL;DR

This paper presents an analytical model showing that disorder-induced variations in charge-carrier density can explain the linear magnetoresistance observed in high-temperature superconductors, challenging the idea that it is a unique signature of the strange metal state.

Contribution

The study introduces a simplified analytical model that reproduces magnetoresistance behavior similar to complex numerical models, highlighting disorder's role in high-temperature superconductors.

Findings

Disorder variations can produce magnetoresistance curves similar to sophisticated models.

Linear magnetoresistance and field-temperature scaling can be explained by realistic disorder levels.

Linear zero-field resistance remains a signature of the strange metal state, but magnetoresistance scaling is not necessarily so.

Abstract

An analytical model invoking variations in the charge-carrier density is used to generate magnetoresistance curves that are almost indistinguishable from those produced by sophisticated numerical models. This demonstrates that, though disorder is pivotal in causing linear magnetoresistance, the form of the magnetoresistance thus generated is insensitive to details of the disorder. Taken in conjunction with the temperature ($T$) dependence of the zero-field resistivity, realistic levels of disorder are shown to be sufficient to explain the linear magnetoresistance and field-$T$ resistance scaling observed in high-temperature pnictide and cuprate superconductors. Hence, though the $T$-linear zero-field resistance is a definite signature of the "strange metal" state of high-temperature superconductors, their linear magnetoresistance and its scaling is unlikely to be so.