A lot of attention has been drawn to superconductivity in ${\mathrm{UTe}}_2$, 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) $B_{2u}$ and $B_{3u}$ of the relevant $D_{2h}$ point group, and it has been argued that the chiral $B_{2u}+i{B}_{3u}$ combination is selected by ferromagnetic fluctuations. In this work we present a possible explanation of the near degeneracy as a result of an accidental $C_4$ symmetry of the band structure, with the superconducting order parameter belonging to the 2D $E_u$ irrep of $D_{4h}$ that uniquely descends to the sought-after $B_{2u}+i{B}_{3u}$ combination. We show that the $C_4$ 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.

• Received 25 April 2022
• Revised 13 June 2022
• Accepted 24 June 2022

DOI:https://doi.org/10.1103/PhysRevB.106.014502