Resistivity saturation in an electron-doped cuprate

TL;DR

This study observes resistivity saturation in lightly doped electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$, suggesting its high-temperature metallic phase can be understood as a low-density metal consistent with the Mott-Ioffe-Regel criterion.

Contribution

It reports the first observation of resistivity saturation in lightly doped electron-doped cuprates, challenging the notion of an inherently strange metallic phase at high temperatures.

Findings

Resistivity saturation occurs at doping level x~0.10.

Saturation values align with the Mott-Ioffe-Regel criterion.

High-temperature phase may be a low-density metal.

Abstract

We report the observation of resistivity saturation in lightly doped ($x\sim 0.10)$ as-grown samples of the electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$ (LCCO). The saturation occurs at resistivity values roughly consistent with the phenomenological Mott-Ioffe-Regel criterion once the low effective carrier density of these materials is included in the analysis. These results imply that, at least for light doping, the high-temperature metallic phase of these materials is not necessarily strange and may be understood as simply a low-density metal.