Simultaneous drop in mean free path and carrier density at the pseudogap onset in high-$T_c$ cuprates

TL;DR

This study links the pseudogap phase in high-$T_c$ cuprates to a simultaneous drop in carrier density and mean free path, suggesting Fermi surface reconstruction and increased scattering are key to understanding the pseudogap's nature.

Contribution

It demonstrates that a Fermi surface reconstruction model explains both Hall number changes and resistivity upturns, highlighting the role of mean free path reduction in the pseudogap phase.

Findings

Carrier density drops from 1+p to p at pseudogap onset

Mean free path decreases abruptly in the pseudogap state

Resistivity upturn linked to intrapocket scattering

Abstract

High-temperature superconducting cuprates are distinguished by an enigmatic pseudogap which opens near optimal doping where the superconducting transition temperature is highest. Key questions concern its origin and whether it is essential in any way to superconductivity. Recent field-induced normal-state transport experiments on hole-doped cuprates have measured abrupt changes in the doping dependent Hall number and resistivity, consistent with a drop in carrier density from $1+p$ to $p$ holes per copper atom, on entering the pseudogap phase. In this work the change in resistivity is analyzed in terms of an antiferromagnetic-order-induced Fermi surface reconstruction model that has already successfully described the Hall number. In order for this model to describe the resistivity we find that the zero-temperature mean free path must also drop abruptly in proportion to the size of the Fermi surface. This suggests that intrapocket scattering underlies the observed upturn in resistivity in the pseudogap state.