2025/03/14 by Husstedt, Freya, Kimata, Motoi, Thadathil, Sajal Naduvile +8
#FOS: Physical sciences #Strongly Correlated Electrons (cond-mat.str-el)
paper · doi:10.48550/arxiv.2503.11525
Details of the electronic band structure in unconventional superconductors are key to the understanding of their fundamental ground state. The potential spin-triplet superconductor UTe2, with Tc≈ 2.1 K, has attracted attention recently. Its main Fermi surface consists of weakly corrugated, two-dimensional Fermi-surface cylinders that run along the crystallographic c axis. In addition, there is evidence for the presence of an additional small three-dimensional band. This has been discussed controversially as it may be essential for the realization of superconductivity in UTe2. Here, we investigate the angle-resolved magnetoresistance and Hall effect in bulk crystalline samples with current along the c axis in fields up to 60 T. We observe low-frequency magnetic quantum oscillations with light effective masses that are most pronounced for magnetic field applied along the a axis. Two distinct frequencies indicate two separate changes in the Fermi-surface topology, likely connected with Lifshitz transitions. We discuss the origin of these oscillations in terms of magnetic breakdown, quantum interference, and other potential mechanisms.