${H}$-linear magnetoresistance in the ${T^2}$ resistivity regime of overdoped infinite-layer nickelate La$_{1-x}$Sr$_{x}$NiO$_2$

TL;DR

This study reveals that overdoped La$_{1-x}$Sr$_{x}$NiO$_2$ exhibits $H$-linear magnetoresistance and $T^2$ resistivity, indicating unconventional transport properties in its normal state, which may be related to its superconductivity.

Contribution

It provides the first detailed magnetotransport analysis showing coexistence of $H$-linear MR and $T^2$ resistivity in overdoped nickelates, highlighting their unconventional normal-state behavior.

Findings

Magnetoresistance is $H$-linear at high $H/T$

Resistivity follows $T^2$ below 30 K

Normal state exhibits unconventional transport properties

Abstract

We report a systematic magnetotransport study on high-crystallinity La$_{1-x}$Sr$_{x}$NiO$_2$ (LSNO) thin films with $x=0.20-0.24$. By conducting pulsed-field transport experiment up to 62 T, we reveal two salient features of the normal-state transport in overdoped LSNO thin films: (1) the magnetoresistance does not follow the Kohler's rule but exhibits a $H$-linear behavior in the high $H/T$ limit and (2) the normal-state $\rho(T)$ below 30 K consistently follows a $T^2$ behavior across the overdoped regime. Our results demonstrate a coexistence of $H$-linear magnetoresistance and $T^2$ resistivity in a model unconventional superconductor and provide new information on the transport characteristics of the normal ground state that host superconductivity in infinite-layer nickelates.