Dr. M. Vališka’s team at MFF UK has successfully prepared high-quality single crystals of UTe2 specifically tailored for quantum oscillation studies. Utilizing these samples, the Cambridge group, led by A. Eaton, conducted a series of experiments in high magnetic field facilities, followed by advanced modelling to assess the potential geometries of Fermi sheets in UTe2.
In this paper, the authors explore the complex superconductivity of the heavy fermion paramagnet UTe2, a material showing signs of spin-triplet superconductivity. Addressing uncertainties about its electronic structure, they conducted magnetic quantum oscillation measurements on high-quality UTe2 crystals. Their findings reveal a quasi-2D Fermi surface, represented by two types of cylindrical Fermi sheets – electron and hole. These sheets display significant undulation but minimal corrugation, potentially facilitating near-nesting that could enhance magnetic fluctuations and the triplet pairing mechanism. Notably, their research finds no evidence of 3D Fermi surface sections in UTe2. The published results provide strong constraints on the possible symmetry of the superconducting order parameter.