A DFT-based review of candidates for the small Fermi pocket in UTe₂

Recently, there have been extensive efforts to understand the low-energy band structure of UTe₂, from which triplet superconductivity emerges from a non-magnetic parent state. Angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT) reveal two sets of quasi-2D Fermi surfaces that emerge from the hybridization of light quasi-1D bands. However, the f-electron band structure is still poorly understood, and has been speculated to be of great importance for the unconventional Cooper pairing. Recent de Haas van Alphen (dHvA) oscillation studies have shown new peaks in the low-frequency regime, hinting at the existence of an additional small Fermi pocket that was not conclusively identified in previous experimental and numerical investigations. I will present a DFT-based exploration of candidate bands. Simulations will be used to evaluate their compatibility with the dHvA and ARPES data as well as the mechanisms that could bring them to the Fermi level. This new Fermi pocket is crucial because it provides a potential channel for Cooper pairing and enhances ferromagnetic fluctuations, which are important for triplet superconductivity.