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

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. In this presentation, I will present our discovery of a nonsaturating, linear magnetoresistance in Mo₈Ga₄₁, a nearly isotropic strong electron-phonon coupling superconductor with a linear-in-temperature resistivity from the transition temperature to ∼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−xSr_xCuO₄, despite the clearly different crystal and electronic structures, and the apparent absence of quantum critical physics in Mo₈Ga₄₁. A new empirical scaling formula is developed, which is able to capture the key features of the low-temperature magnetoresistance data of Mo₈Ga₄₁, as well as the data of La_2−xSr_xCuO₄.