Anisotropic signatures of the electronic correlations in the electrical resistivity of UTe$_2$

TL;DR

This study investigates the anisotropic electrical resistivity of UTe$_2$ under high magnetic fields, revealing how electronic correlations and magnetic fluctuations influence its behavior, crucial for understanding its unconventional superconductivity.

Contribution

It provides a detailed analysis of resistivity anisotropy and critical behavior near the metamagnetic transition, highlighting the role of magnetic fluctuations and electronic correlations in UTe$_2$.

Findings

Identification of two characteristic temperatures and an anisotropic Fermi-liquid coefficient A.

Critical behavior near the metamagnetic transition at 35 T for H parallel to b.

Evidence of anisotropic scattering processes and magnetic fluctuation contributions.

Abstract

Multiple unconventional superconducting phases are suspected to be driven by magnetic fluctuations in the heavy-fermion paramagnet UTe$_2$, and a challenge is to identify the signatures of the electronic correlations, including the magnetic fluctuations, in the bulk physical quantities. Here, we investigate thoroughly the anisotropy of the electrical resistivity of UTe$_2$ under intense magnetic fields up to 70~T, for different electrical-current and magnetic-field configurations. Two characteristic temperatures and an anisotropic low-temperature Fermi-liquid-like coefficient $A$, controlled by the electronic correlations, are extracted. Their critical behavior near the metamagnetic transition induced at $\mu_0H_m\simeq35$~T for $\mathbf{H}\parallel\mathbf{b}$ is characterized. Anisotropic scattering processes are evidenced and magnetic fluctuations are proposed to contribute, via a Kondo hybridization, to the electrical resistivity. Our work appeals for a microscopic modeling of the anisotropic contributions to the electrical resistivity as a milestone for understanding magnetically-mediated superconductivity in UTe$_2$.