Chiral superconductivity in UTe₂ via emergent C₄ symmetry and spin-orbit coupling

A lot of attention has been drawn to superconductivity in UTe₂, with suggestions of time-reversal symmetry breaking triplet chiral superconducting order parameter. The chirality of the order parameter has been attributed to an accidental near degeneracy of two superconducting components belonging to one-dimensional (1D) irreducible representations (irreps) B2u and B3u of the relevant D2h point group, and it has been argued that the chiral B2u + iB3u combination is selected by ferromagnetic fluctuations. Here we present a possible explanation of the near degeneracy as a result of an accidental C₄ symmetry of the band structure, with the superconducting order parameter belonging to the 2D Eu irrep of D4h that uniquely descends to the sought-after B2u + iB3u combination. We show that the C₄ symmetry is emergent at the level of the interactions using a renormalization group calculation and argue that the chiral combination of the order parameter is favored when spin-orbit coupling is added to the model.