Linear magnetoresistance with a universal energy scale in a strong-coupling superconductor

TL;DR

This study reports a universal linear magnetoresistance in a strong-coupling superconductor Mo$_8$Ga$_{41}$, showing similarities with cuprate superconductors, and introduces a new empirical scaling formula to describe this phenomenon.

Contribution

The paper uncovers a universal linear magnetoresistance in Mo$_8$Ga$_{41}$ and proposes a new empirical scaling law applicable across different correlated electron systems.

Findings

Linear magnetoresistance observed in Mo$_8$Ga$_{41}$

Resistivity growth in magnetic field comparable to temperature growth in energy units

Scaling formula captures magnetoresistance features in diverse materials

Abstract

The recent discovery of a nonsaturating linear magnetoresistance in several correlated electron systems near a quantum critical point has revealed an interesting interplay between the linear magnetoresistance and the zero-field linear-in-temperature resistivity. These studies suggest a possible role of quantum criticality on the observed linear magnetoresistance. Here, we report our discovery of a nonsaturating, linear magnetoresistance in Mo$_8$Ga$_{41}$, a nearly isotropic strong electron-phonon coupling superconductor with a linear-in-temperature resistivity from the transition temperature to $\sim$55 K. The growth of the resistivity in field is comparable to that in temperature, provided that both quantities are measured in the energy unit. Our datasets are remarkably similar to magnetoresistance data of the optimally doped La$_{2-x}$Sr$_x$CuO$_4$, despite the clearly different crystal and electronic structures, and the apparent absence of quantum critical physics in Mo$_8$Ga$_{41}$. A new empirical scaling formula is developed, which is able to capture the key features of the low-temperature magnetoresistance data of Mo$_8$Ga$_{41}$, as well as the data of La$_{2-x}$Sr$_x$CuO$_4$.