using Sagnac interferometry.*

The heavy fermion compound UTe₂ was recently found to superconduct with T_C = 1.6K, showing paramagnetic behavior and closely resembling the family of uranium based ferromagnetic superconductors [Ran et al., Science, 2019]. This initial study presented strong evidence of spin-triplet superconductivity, likely mediated by ferromagnetic fluctuations, which have been shown to occur below T_C in μSR experiments [Sundar et al., arXiv, 2019]. Additionally, a recent scanning tunneling microscopy experiment claims signatures of chiral modes inside of the superconducting gap, raising the possibility of topological superconductivity [Jiao et al., arXiv, 2019]. A direct measurement of possible time-reversal symmetry (TRS) breaking effects in this system can provide insight on the exact order parameter of UTe₂, as well as evidence for the possible topological nature of the system. We present measurements of the polar Kerr effect using Sagnac interferometry in search for a possible TRS breaking state, and to examine ferromagnetic fluctuations in the Meissner and vortex states of this material.