Theory of Resistivity Upturns in Metallic Cuprates

TL;DR

This paper explains the low-temperature resistivity upturn in cuprates by modeling disorder effects in a strongly correlated Hubbard model, showing that magnetic droplets around impurities cause increased scattering and resistivity.

Contribution

It introduces a novel explanation for resistivity upturns in cuprates by linking disorder-induced magnetic droplets to enhanced scattering within a correlated electron framework.

Findings

Magnetic droplets form around impurities due to correlations.

Disorder-induced magnetic scattering causes resistivity upturns.

Pseudogap enhances magnetic states and resistivity effects.

Abstract

We propose that the experimentally observed resistivity upturn of cuprates at low temperatures may be explained by properly accounting for the effects of disorder in a strongly correlated metallic host. Within a calculation of the DC conductivity using real-space diagonalization of a Hubbard model treated in an inhomogeneous unrestricted Hartree-Fock approximation, we find that correlations induce magnetic droplets around impurities, and give rise to additional magnetic scattering which causes the resistivity upturn. A pseudogap in the density of states is shown to enhance both the disorder-induced magnetic state and the resistivity upturns.