Jan Prokleska

Charles University, Prague, Czech Republic

Peculiarities of Electronic States in Uranium Intermetallics

In this talk, I will present the results of experimental studies on two uranium-based systems under multi-extreme conditions.

The first system involves the investigation of quantum phase transitions and the impact of purity on the nature of these transitions. We demonstrate that by alloying the compound UCoAl with a sub-percent amount of Ru, the system can be driven, either by pressure or substitution, to and across the tricritical point. This allows us to trace the first-order transition line leading to the theoretically predicted quantum phase transition.

The second presented system is UTe₂, a material with multiple superconducting phases. In collaboration with the Cavendish Laboratory, a detailed investigation of its electronic structure at high magnetic fields using high-quality samples has been conducted.

As a bridge between these systems, I will also discuss the investigation of the tricritical point in both systems through the study of their elastic properties.

References:

2307. Valiska et al. Dramatic elastic response at the critical end point in UTe2, https://arxiv.org/abs/2307.01884
2308. I. Weinberger et al. Quantum interference between quasi-2D Fermi surface sheets in UTe2, https://doi.org/10.1103/PhysRevLett.132.266503 and references therein
2309. Opletal et al., Quantum ferromagnet in the proximity of the tricritical point, https://doi.org/10.1038/s41535-017-0035-6

Acknowledgement: support by Grant Nos. 16-06422S and 22-22322S of the Czech Science Foundation.