Fermi-surface reconstruction at the metamagnetic high-field transition in uranium mononitride

TL;DR

This study investigates the electronic and magnetic changes in uranium mononitride under high magnetic fields, revealing a Fermi-surface reconstruction associated with a metamagnetic transition at around 58 T.

Contribution

It provides the first detailed experimental evidence of Fermi-surface reconstruction during a high-field metamagnetic transition in uranium mononitride.

Findings

Identification of a sharp first-order-like transition at 58 T.

Suppression of magnetic contributions to resistivity in high-field state.

Evidence of Fermi-surface reconstruction from Hall effect measurements.

Abstract

We report on the electronic and thermodynamic properties of the antiferromagnetic metal uranium mononitride with a N\'eel temperature $T_N\approx 53\,$K. The fabrication of microstructures from single crystals enables us to study the low-temperature metamagnetic transition at approximately $58\,$T by high-precision magnetotransport, Hall-effect, and magnetic-torque measurements. We confirm the evolution of the high-field transition from a broad and complex behavior to a sharp first-order-like step, associated with a spin flop at low temperature. In the high-field state, the magnetic contribution to the temperature dependence of the resistivity is suppressed completely. It evolves into an almost quadratic dependence at low temperatures indicative of a metallic character. Our detailed investigation of the Hall effect provides evidence for a prominent Fermi-surface reconstruction as the system is pushed into the high-field state.